OSX 10.11.2, NVIDIA GeForce GTX 680MX 2048 MB
Short description of error
I'm not 100% sure if this will be agreed to. When using Absolute Grid Snap in orthographic views (e.g. Top), I would have expected the snap to limit itself to X and Y, I can make this happen by pressing Shift+Z. Ether an option to only snap in 2 dimensions - perhaps a modifier key? would be really nice.
Exact steps for others to reproduce the error
Based on a (as simple as possible) attached .blend file with minimum amount of steps