I finally had to change the A2 aperature to a A1 to tighten up my groups.  The large hole A2 sucks.  

Gee, I really like it.

The large hole for screwing around....hmmmm that doesn't sound so good, do it?

And the small aperature for serious stuff.

I like it so much that if I ever get around to getting another fixed sight upper I'll put the A2 aperature in it.

I've never used the large aperature. Even in the 4 years I was in the Airborne Infantry, I don't recall ever using it.
AIRBORNE!

Quoted: Gee, I really like it. The large hole for screwing around....hmmmm A2 a

I prefer the tighter hole myself

Never used large apeture in 16 years of shooting ARs , looser than my last girlfriend

I hate the A2 front sight post-

Was used to my M1-A sight post, and when I tried doing some 100yd stuff for the first time with my AR, I realized what a big black telephone pole I had blocking the center of the target.

For $12.95 I ordered a new .052" front sight post from the new Bushmaster catalog, very close in dimensions to my M1A sight, and I can actually see the center of the target at 100yds now.  Very cheap, long distance shooting improvement, and dropped right in to replace the A2 front sight.