It's easier to list the changes that 'didn't' make it worse,........
1)The square post front sight gives better definition in differing light conditions.
2)The closed bottom birdcage doesn't kick up dust like the A1.
The rest of the changes make it a range pig adding doodads and weight. If you like the longer stock, fine. I'm 6-1 and have no problem with the earlier stocks. Trap door? Extra weight and parts. The A2 sight is great on the range,......not so great in the field. Adds weight and too many parts and encourages fiddling. The round guards are a bit tougher but their primary purpose is to allow one item in inventory instead of two(left and right). A2 grip,......meh. If it fits you it's OK. A2 receiver reinforcements are OK. A bit stronger,......very minor weight change. A wash. Three round burst sucks. It's a poor replacement for training and it adds parts/complication to the trigger mechanism while ruining the trigger feel, and it can give either one, two, or three rounds depending. Really lousy design.
The big change is in the barrel. The weight was increased forward of the gas port so the barrels wouldn't bend when the rifle was used as a pry bar. It serves no other purpose. The 1:7 twist was 'needed' to stabilize the longer tracer round to 1000m in sub-zero temperatures. Pigging the thing out completely ruined the rifle.
It's all about weight and simplicity. The M16A1 is still a light, handy rifle. The M16A2 isn't and the changes were all made for stupid reasons.
