I've a used Nokia X for a little period of time and really regretted my decision of doing so. It's a very bad phone to feel and use.
Nokia X is a small budget phone with a Snapdragon processor and ½GB ram. It's has a small 4inch display 4GB internal storage and 3MP back camera to shoot images. All of these features seems very low and it's because it really is.
The main problem is not all these however. Nokia have a custom version of Android installed in Nokia X that doesn't allow the installation of many Android apps. There is no Google playstore in Nokia X and it can't be install any normal way. Only if you're rooted, that's possible. I had to do it that way, bit for a normal user that's not possible.
Only a selected few apps can be installed and this limits the phone usability to a very low level. And also most of all the common games don't work in the device as well. Buying a proper android phone from any other company will be a very better choice that the Nokia X.
