I have the following.......
USPc .45
USPf .45
USPf .40
HK P30
All of which are outstanding pistols! I carry the full size USPs during the winter with a jacket or large sweat shirt, because it is a large framed pistol. I carry the compact USP as my primary CCW. I have absolutely no problem concealing it using my CTAC inside the waistband holster. I rotate the P30 (9mm) into my CCW rotation every now and then, but I just love my .45s!!
I would recommend buying one!! CDNN is probably the best place to find one at a reasonable price.
By the way, the HK45 and HK45c are the supposed to be "upgrades" to the USP line. I wanted to buy the HK45, but in these times rifles and ammo come first.