I had the Choate +2 extension but never got around to installing it. When I went to put it on something just did not seem right so I ordered a Wilson Combat +2 extension. I did not like everything about the WC either. Bottom line, I ended up using the tube and clamp from the Choate and the spring and follower from the Wilson Combat. Be prepared to spend some time dremmeling out, sanding and re-blueing the mag spring stop retainer dimple. I think that overall the Choate is one of the better ones for the price.