ACI actually does make pretty decent barrels, they are ceramic coated and shoot cleaner than a normal finish.
They're stepped bore and subscribe to the same theory that all those high end barrels do. Stainless steel back that fits your paint and an overbore second half.
And they're large bore, so you can shoot many types of paint without worrying. However, you will get best performance out of a good match though.
All in all a great barrel for the money!
And what's wrong with ACI's products? I've been running them for the six years I've been playing, in fact if I remember right I play for them!