There are many phones which ship with the Windows Phone operating system. But are there any features of the operating system or certain hardware that some phones don't support? What other factors should I consider when choosing a device?
Note: This answer has been made community wiki, feel free to amend it with more factors.
Smaller screen sizes are useful when you don't plan to do more than using it as a Phone: calling, messaging and occasionally using it to for one of its extra features.
Bigger screen sizes are useful when watching multimedia, watch out though because those fit less well in the pockets of your trousers and might require a different way of transporting your Windows Phone.
All screen sizes currently have the same resolution of 800 x 480 pixels.
There are different screen types out there (S-LCD, AMOLED, Super AMOLED) which all have their specific characteristics. Things to consider here is battery usage versus clarity, which kind of depends on where you are planning to use your phone the most (indoors or outdoors) and how clear you need the screen to be.
Watching some comparison videos on the different types (on a site like YouTube) gives a good idea about how these differ. Be sure to at least check the screen type out before standing in front of a surprise where the sun disallows you from reading the screen properly, reviews test reflection too...
When you plan to use your phone for calculations and some mobile gaming, you need to consider whether you will want some extra processing power. You also want to make sure that you don't have a phone slower than all the others, unless you don't really need processing power, but just a Phone.
Most devices come with the same amount of memory, watch out because there however are devices that come with less memory and would limit the amount of applications that can be ran simultaneously (as well as disallow memory intensive applications).
If you somehow need a lot of memory, you should be on the look for upcoming phones.
The internal memory is where all the persistent application data, music, photos, videos and similar multimedia gets stored. The size here matters if you plan to use your phone as a music player, to take a lot of photos or to watch your favorite serie/movie while on public transit, or something along those lines.
The Zune player allows you to specify the border between application data and your multimedia, so keep in mind that 8 GB with for instance 10% applications leaves you behind with 7.2 GB for multimedia and 0.8 GB for applications.
The most recent Windows Phones have a Near Field Communication transponder. Uses for this are limited at this time, but it will get increasingly useful over time, in certain parts of the world.
If you like taking a picture occasionally, be sure to check out what lens is being used and other characteristics the amount of MP, the resolution, the use of scaling and so on. If you want to take videos, you might even want to go further than that, as well as check whether the phone has stereo audio recording if you feel like you'd need that.
Mainly for video calls, video recording apps, and perhaps useful as a mirror too.
External Storage Card Slot
Hot swapping an SD card is not currently supported by the Windows Phone OS. However, if your device does have an SD slot you can upgrade your memory up to 16GB. You'll need to hard-reset the device and format the SD card. This is a list of SD cards and their compatibility level with Windows Phone:
Confirmed Working(Data remains after soft reset):
•Kingston 4GB Class 4
•Kingston 8GB Class 4
•Kingston 32GB Class 4 •Microcenter 16GB Class 2
•SanDisk 8 GB Class 2
•SanDisk 16GB Class 2
•SanDisk 16 GB Class 6
Currently Unstable: •SanDisk 32 GB Class 2 (Confirmed working by Rok17 )
Confirmed Not Working(Data gone after soft reset):
•A-Data 4GB Class 6
•A-Data 16GB Class 6
•Lexar 16GB Class 6 •Transcend 8GB Class 6
•Transcend 16GB Class 6
Other than that, you can use WiFi to upload your data online or sync over the network with your computer, or use the mini USB cable to connect it to your computer and sync that way.
If you don't feel like touching the screen, a keyboard can feel more physical and thus be more useful if you'd rather prefer that. Reviews might be able to help figure out of what quality the keyboard is.
All Windows Phones have a minimal set of sensors that will include A-GPS and a Accelerometer. However there are more sensors available which are optional in a Windows Phone device. The optional sensors are the already mentioned Front and Back camera and the Compass and Gyro. The last two can be used to create apps that respond to the direction your looking at (compass), or to determine how you are holding your device.
Most vendors have their own marketplace where they publish apps only available for users of their brand devices (Nokia, HTC). Within these marketplaces their are apps that can be pretty handy for users. For example: In the Nokia marketplace there is (for Nokia users) free navigation app called Nokia Drive. With this free app brands are creating a better total phone experience exclusive for their users.
Seeing that you are asking for "features of the operating system or certain hardware that some phones don't support?" I would assume that you are afraid of finding apps that doesn't support your phone? Generally speaking, there are three types of Windows Phones, the first generation phones, the Mango phones, and the Tango phones. Most of the first gen phones have similiar hardware (1GHz processor, 512 RAM, 8GB/16GB of internal memory). These phones don't have front facing camera nor gyroscopes, and aren't 4G/LTE capable. Some unbranded phones still receive the most recent updates, but upgrading to Windows Phone 8 (coming out later in the year), isn't guranteed. The Mango phones carry slightly higher spec, with 1.4/1.5GHz processors, some of them have front facing camera and gyroscopes. I would recommend getting one of these since they are rumored to be supported by Windows Phone 8. Some of them carry 4G capabilities too. The Tango phones are the newest addition to the WP family, with Nokia Lumia 610 taking the lead. These are the ones to look out for. They only have 256MB of RAM, which means some popular apps aren't available on these devices (Angry Birds, Photosynth etc). A flavour of Lumia 610 supports NFC.
Personally, I would suggest getting one of the Nokia phones, they've put in some big money into exclusive apps and Windows Phones are their last hope, so they care about their customers a lot more than the other companies. The Nokia Lumia 900 should be the one to go for.
It just depends on what you need and what you want (and your budget too).
- Will you mainly use it for calling people or for activities related to apps (internet, games, social networks and so on)? If you want a phone choose a lower end device. Otherwise if the phone is just a feature amongst the other, higer end devices may be more convenient for you.
- Do you want a gaming machine? If you don't want it you may not need lots of RAM and a 512 MB may be enough for you. But if you want to play with your phone, you will need lots of RAM (1 or 2 GB) and a higher end phone (Lumia 820 at least). But to be really honest do not choose a Windows Phone smartphone in this case despite Xbox. Choose an Android or an iPhone.
- Will you use the camera a lot? If yes choose a Nokia, especially a PureView one.
- Think to the space that the phone will take (in your pocket for example), and if you want to use it with one hand only or both hands. If you really want to avoid cumbersome phones, avoid the phablets (Lumia 1520 and 1320) and perhaps the Lumia 625 and the higher end phones (which usualy get bigger screens than the lower end devices).
- Do you plan to use the GPS a lot? If yes choose a phone with HERE Drive+ included. HERE Drive+ can be used on other Windows Phone but you will have to pay for it.
- Do you want geeky features just like wireless charging or lossless cameras? In this case higher end devices are for you.
- As for the Windows Phone version ensure that it is Windows Phone 8 or higher. Windows Phone 7 has got too much limits and is not very supported too. New apps are rarely WP7 compatible.
- Do you need lots of memory storage, for your music, your videos, your pictures and perhaps your podcasts? If ensure that you can have at least 32 GB, with an external storage or not. Moreover be careful: apps cannot be installed on the external storage.
- Will you do video calls (i.e. Skype or Whatsapp) with it? If yes ensure that you have a good front camera.
- Do you fear a potential lack of apps on Windows Phone? If yes choose Android or an iPhone.
- What is your budget? The more money you have, the highest devices you can afford.
As for the brand choose a Nokia, the only manufacturer which is really committed in Windows Phone.
Surprisingly no one mentioned SAR value. This, basically, is the amount of radiation that the phone will expose you.
Nokia Lumia series, unfortunately, has a (very) high value, above 1 (zero being ideal).