i have two kydex iwb's, one galco, can't recall the other, both with tension screws.
why two, different trigger guards on the two 229's, one rounded on the sas2/no rail and square on the sct/rail, so tension isn't the same for both.
so i use a nylon, #16 uncle mike's for the 23, both 229's, p6 and g27. it's comfortable, enough tension between my body and the holster.