I'm gonna go with Jon on this, the sig p220 is a great da/sa. Reliable, accurate, and feels good. I had a USP 45 full size, and it is easily the biggest pistol I've ever owned. Very unergonomic and bulky, it did shoot ok and it shot no matter what I put in it. The only plus I see on USP is capacity, but you can get that from Glock, FN, XD, or S&W M&P.
Its made open carry cause you can't hide, should have large hands to hold the gun and operate the safety and mag release. If your taking it to war and you got the hands for and it feels comfy for I say go for it, but it's just not for me.