Recs.
Updated
SpecsUpdate
Pros
Pro Smooth performance
Lumia 635 runs Windows Phone 8.1 and has a quad-core 1.2GHz Qualcomm processor, 512 MB of RAM and Adreno 305 GPU.
Since the introduction of the Windows Phone 7, devices run smoothly on hardware that on paper should prove problematic. The Lumia 635 continues that trend with smooth navigation. Its lower spec processor is only evident in processor intensive situations such as loading or downloading applications.
Pro Bright design and solid build quality
The 635 can only be purchased in black or white but is available with replaceable shells that come in black, white, orange, green, and yellow. Despite the removable backs and the low price of the 635 still feels like a phone that will hold up to the abuse of daily life.
Cons
Con Subpar 4.5" 854x480 LCD display
Pixels are somewhat visible on the 635 with a PPI of only 221. The 635 also does not feature extreme touchscreen sensitivity for using gloves like the Lumia 520. Fortunately Nokia's ClearBlack technology that improves outdoor readability is included. The display is also protected by Gorilla Glass 3.