I switched around. I have the REI Minimap mod installed on my 1.7.2 profile so I sometimes use that. I use 1.8 if I'm working near the bedrock on my res so I can see properly. Other times I use 1.7.9 or 1.7.10 for no reason really, just to do it.
Figured I should share as well I'm on 1.7.10 myself. I started with 1.7.5 which I used to connect to some other servers, but right now I'm mostly using 1.7.10. I have been playing with 1.8 in single player (survival) but that's basically it, I'm also one of the many who experiences major performance issues while 1.7.x works normally. So most of the time (either single or multiplayers) I'm on 1.7.10