Just finished putting an ACE skeletonized stock on and I ran into a minor problem. Not with the stock, with the extension tube. The diameter of the extension tube grew near the receiver end. I could slide the stock on almost all the way except I couldn't get it on the last 3/8". I swapped extensions with another rifle that used the standard A2 stock and they both worked fine. The swapped tube didn't change diameter so the Ace fit well and the A2 stock apparently didn't care about the over-dimension as it fit too.
I don't know if tubes are prone to this or not. Perhaps I got a bad tube tube? Anyway, heads up.
So far as the stock goes.....Wow!! I've been waiting for something like this for a while. I really didn't want to buy a non-operating, telescoping stock. I'm glad this was available.