Re: AIAE - muzzle brake or not???
Personally, I think they definitely have their benefits, but on an AE they're not a mandatory item - leave it up to personal preference. Recoil is not, in my opinion, an issue with an AE or AW. My 24" AE shoots just fine without a brake, and getting a barrel threaded and a brake installed is a relatively inexpensive and straightforward process. The main benefit is in making it easier to stay on target through recoil, and the main drawback is the noise and blast. Both tend to be inversely related, so it's a question of just how much recoil reduction you need, and how much blast you can live with.
IMO, the difference between the 20" AE with muzzle brake, and the 24" without is relatively minor either way. With that said, if I were to pick an ideal all-round AE, it would be a 20" folder with muzzle brake.