I wear a 2Xl glove. I like the MOE grip mine came with over the standard AR grip. The added portion at the web of the thumb increases the reach to the trigger which is very nice for me. I've wanted to try the MIAD kit to see what the different backstraps feel like (it comes with 3) but I haven't had enough spare funds to justify replacing something I don't feel needs to be.

Most grips wont vary much in thickness due to the grip needing to taper flush to the lower receiver so the safety can clear it.