The 226 doesn't come in .45.
I have several Sig 220's (ST, Rail and stnd) in .45, and in my personal biased opinion, since I teach for SigArms, it's the best all round .45 you can buy in terms of accuracy, longevity, and plain simplicity to use.
That said, I've ALWAYS shot better with a 1911 frame gun, they just sit in my mits better, and I have multiple Kimbers and a couple real high end Baers and one Valtro.
No matter what you chuck it through, the .45 is the best all round ..round, next to .357SIG anyhow.
As for HK's, I have a SOCOM in .45, but it's the only one of their models I have seen break in less than 4 months use on our range, and I've probably had a dozen USP's have slide fractures and other issues. That's on a very VERY busy range however, most folks never shoot that much. I've never had a 226 or 220 go down with anything more than a 2 dollar spring issue, and one of my 226's is pushing 150,000 rounds. I really like the HK's though, and their dual spring system in the slide makes it the easiest pistol out there to cycle, so when you're doing one handed pistol drills, racking the slide off your heel or belt/holster is easy as hell compared to a Sig weapon.