It's always seemed to me that the A1 was more of a true "assault rifle" along the same line of thought as the original Nazi types. Sort of a hulked-out submachine gun with 300 or 400 yard rifle capabilities.
With the A2, it seems like they moved back towards the older "battle rifle" concept somewhat, restricting the full auto to burst fire and putting more emphasis on the long range accuracy end of it. I'm not saying this is regression, by any means, just different priorities.
I've never fired an A2, but from what I hear of the way the trigger pull varies from shot-to-shot in a 3-round cycle, I'd have to say they botched the job a bit if a precision rifle was the goal. That would drive me nuts. I also wonder about the ruggedness of the fancier back sight.
I think I would prefer the A1 for most use.
But maybe they got both the A1 and the A2 wrong. For well-trained, intelligent marksmen who baby their equipment, the A2 range-adjustable rear sight and the A1 full-auto option could both be put to their best use. The great unwashed and undisciplined masses might be best off with the "baby-sitter" 3-round burst limitation of the A2 and the more idiot-proof sight setup of the A1.
[:\]