Hi Aaron and Welcome.

I don't have any experance with the Sig. I do have the G20 which is the "Twin" of the 21, They're identical except the caliber. I like it, I never have had any problems with it. it is big the same size as a full sized 1911A1.

I know there are a couple of guys with Sig's on the Board, I don't know if they're 220's,or not. so maybe they could clue You in as too it. If not,Sigfourm.com is an excellent source of info on the Sig, one of the Co-owner's is a member here.