i can vouce for a browning hi power .40, which is almost the same as a 1911.
Had the blade-tech iwb for abotu 3 years. was very nice, but it wouldn't move as I moved, i.e. when i sat down in the car, etc.
I now have the comp-tac IBW which has leater between the holster itself and the j-clips which slip over the belt. That makes it able to move a slight bit when i bend or sit. As far as gun security, they're both top notch. But the comp-tac is just more comfortable if you get in/out of a car, etc.