the green arent terrible,never had any others(orange/black/etc)...
but Magpul followers(gen II) go in all of my USGI mags and are much better than the green.i think they have a gen III now,but i havent tried them and the gen II are great.
the Pmags come with them.
im pretty sure if you're going to stick with what comes in them...go with the green.but changing them out for Magpuls is by far the best way to go that im aware of.
I installed the green followers I got from Brownells in my 30 rd mags. They seem to be very stable and working very nice even in the very bad practice after market mags.