I really do like the full stock feel of an A1 or A2 for my 450 Bushy. I tried the M4 stock for a while, but for me, it was not comfortable. But then, I find the M4 uncomfortable on my XM15 too. It's probably just a matter of personal preference. But since my A1 is a Noonan stock, you must consider that I may have a bias towards full stock styles due to Gunnys' recoil-less design. When it all boils down to the fat, whatever YOU like is the best for you.