After putting the extended mag release on my G27 gen3 I have quickly noticed that the button digs into my back and am going to go back to the low profile release. Its not a factor when using my Crossbreed deluxe(non combat cut) but definitely with my Milt Sparks VM2 . I lean toward the Vm2 due to the fact that it doesnt interfere with the upgraded sights.On my CBST, Ive noticed a dig mark on the kydex so dont want to knock my sights out of whack. JMHO on leather holsters in this matter