Im a windows-phone user and I have been using it since the sad windows-mobile 6 era... I used my LG E900 WP7 device for a year and have its mainboard replaced free under warranty when the screen says the internal storage is corrupted.
Phone lives for another 2 years, until I decided it's time for me to try WP8. I picked up a Nokia 520 and was happy with it. Until the softkey stopped working just after the 1yr warranty period ended.
Then, because I also own an entry-level Hisense Android phone, I looked at Nokia X including some of its android competitors. The nokia UI is slow, unintuitive and terrible, they should just admit they are selling an android phone, not a windows phone.
If Nokia 520, praised for its good performance for an entry level device, fails me, I couldn't possibly recommend its half-hearted brother Nokia X.
In the end, I went for WP again (Lumia 625) because of the Nokia Here Drive and the fact that it doesn't froze so often.
I don't know if Nokia purposely make Nokia X so slow so people would get a windows phone or what, but I know they are not doing their company a good favor.