Well, there are plenty different models to be had, from a compact version, to the larger expert/elite/tactical versions.
The compact 45 is one of the feeling handguns I have ever owned, fits the hand perfectly. It only holds 8 rounds standard, but it is a compact. The standard size USP, you can get with 10 or 12 round magaines (same for the expert/elite/tactical). I also have a Tactical 45 USP, and it is just sublime. O-ring barrel, match grade trigger, match sights, and threaded barrel, make for one really nice toy. I can get away with concealing it just fine, and its larger brother the mk23, in the winter.
The only real downside to HKs is the cost of magazines, but I have gotten over that. Check out the HK forum if you want to see pictures, and other information. Tons of info there.