The ATI is a piece of junk, just about everyone that's had one said they were somewhat toy like, I wouldn't recommend it to anyone. One member put one on a rimfire Sportster for is little boy, that's the only place I can see it being worth it.
Chad, as you found out, the adjustable butt pad is in another thread, that's why I split it off, Jess bought the Choate stock which is adjustable for length of pull and has 2 different cheek pieces that can be added optionally.
Tim