is it recommended to change out the green followers in USGI mags?  what is best to use and why?  thanks.

Green followers are fine.

I agree.  Green followers are fine.  I like the Magpul better.  That is what I have in all my mags.  But if you want some extra greens, I can send you some.  I have 3 or 4 extra I can send you.  Just e-mail me your address.

Well shit, can I have some too?

Green are fine. I have several mags with the old black followers and have never had any problems.

I am so behind the times I just changed the followers in about ten of my mags to green from black. Some of these mags I bought new around 1989 or 1990. I've never had a problem with the black ones, but I found green followers cheap on the EE so I decided that all my mags should at least have the same color follower.

I don't have a metric ton of mags, but all of them have green followers and function 100%.  I recently priced some new mags from one vendor:  10 mags w/ green= $89.95.  Those same mags with Gen2 Magpul followers= $111.85

From another vendor, again with Magpuls= $109

The argument is made that green or black followers can tilt and cause jams, so go with the best.  I agree.....if you are running your AR hard, in less-than-optimum conditions, and relying on it to save lives.

Just yesterday, I spent a few hours shooting ARs with another board member, and neither of us experienced a failure of any kind with the green followers.  Yea, we weren't shooting fast, dumping rounds downrange and working in dusty conditions.  If you are, get the best stuff on the market to limit your chances of dancing with Mr. Murphy.

If you're looking at a bulk mag purchase in the near future, you might as well get the Gen2 followers already installed for the simple reason that I can't hurt and doesn't cost that much more.  If you are experiencing problems with a particular magazine, changing the spring and follower with better might just fix the issue.  Otherwise, run with the green and don't feel left out.