IMO the A2 is the best performing flash hider on the market for the price, without an annoying ting from prongs that get caught in the brush, and with a closed bottom so it won't kick dust up into your face from prone.
Honestly, why not just get a 16 in barrel? If you have to pin something in place to get to the same length, I'd rather just have that tiny bit of barrel for an extra 100 fps, not to mention restricting future changes like gas blocks, or free float hand-guards.
If its faster, and tighter groups you're after, put that money towards some training and ammo.