Seriosly it all comes down to the comfort and accuracy you feel, and ergonomics for you in particular, and price range for you. Here is a copy of what I posted on another thread that compared the Hk USP45 and Sig P220. As you've said, I definitely know that I will own an Hk in the future and maybe soon, but I chose to get the Sig fist for my own reasons. Sig and Hk are simply the best handguns to me. As far as Glocks go, I have never had any good experiences with them though I have shot many of them many times. If you can't say anything nice, I guess don't say anything at all.
"It's funny how this comparison topic b/ these two great .45's, often come up both here and other forums, cause I was in the same exact dilemma a year ago, hehe. When I was ready to purchase my own .45 last year, I researched alot, asked around alot, and tried out .45's alot, including both the P220 and USP 45. The Glocks and others were weeded out very early in the competition for getting my investment. It came to a dead heat showdown b/ the Hk and Sig! the one thing I learned was to not trust opinions of others, esp if they don't own either of the guns. After meticulous questioning at ranges and shops, etc. It seemed to be an even favoritism to both the P220 and USP45. Then you find out that the guy who votes Hk had an Hk and perhaps only fired a Sig once, hehe. Well here is my personal opinon and not for you to take in because I said it. I found out for myself as well as many have said, that the Hk is very durable with its design and finish. I also find it a bit nicer looking than the Sig. But the Hk is a plastic polymer frame and am not too fond of plastic frames. But the Hk though plastic frame, was not too top heavy and though had more recoil than the P220, it recoiled pretty nice. The accuracy was about the same as the P220, but I found the Sig to be more accurate but not by much. Depends on distance. The farther you went, the more accurate th Sig became over the Hk. The Hk is also a bigger gun and good if you have HUMONGOUS hands. But I like the feel and comfort of the Sig much much better than the Hk. To sum it up, the better gun to me won, which is the Sig P220. I love it to this day and occasionally rent an Hk USP .45 to shoot alongside my P220 and I still feel good about my original decision of getting the P220 over the Hk. Sig is a bit more accurate with less recoil, with a more comfortable feel and hold. Sig has an aluminum alloy frame which I like over the polymer frame of the Hk. Both very reliable and neither jammed once for me or gave me problems. The Sig is simpler and easier to operate and cost a bit less than the Hk and even as you said, "if priced the same", I would still get the P220. It is just a damn good gun! The bottom line here is to go out and see it for yourself and compare the two like i did. Who knows, you may feel otherwise. Good luck." [Quoted]