I have ATI + aluminum package and it works really nice for me, really stable, no wobbling. Maybe aluminum parts are better fitted or something. Side folding is very nice for transportation. No bedding was necessary - fit was good as is.
The only thing I've changed/fixed - the pistol grip is attached by a self-threading screw, into plastic stock, which seems weak - I've replaced this with a brass threaded insert into the plastic of the stock and 8-32 bolt. (But, from what I saw - the same screw/plastic is used on Tapco stocks)