I just finished evaluating 3 AIWB holsters, a Bravo Concealment Acer DG2 with combat suede, Appalachian Concealment Katana and Gladius.
Until my very recent switch to the FNS-9, I've been carrying exclusively AIWB for the past two years a Glock 17 in a Phlster Access holster and single mag pouch (I re-purposed the mag pouch for the FNS-9 magazine). Regrettably, Phlster only makes holsters for Glocks and M&P's.
Now on to these 3 holsters.
My favorite by far is the Appalachian Concealment Katana. Well crafted, fast turn around time (under 2 weeks), and incorporates a very clever molded in wedge that helps keep the grip tight to the body. Ride height and belt loop width are adjustable. I ordered a zero cant but you can order one with a cant. Other colors are also available. The one man shop owner, Matt, is a super guy to work with too.
The Gladius is more than just a Katana with a belt clip arrangement. It has a redesigned outer face to handle the belt clip. This gets second place because my personal preference is a belt loop, but if you prefer a belt clip then this is for you.
I do not like the BC Acer DG2. Perhaps as an IWB it's OK, but I tried fitting it using all sorts of configurations (single attachment in the front, single in the rear, both, etc) and the end result was always the same: the gun rode too high and just didn't conceal as well.
Hope this helps.