I do own at one time or another every USP model ever made as well as several the P7 series (P7PSP, P7M8, P7M13, P7M10) and P9S pistols. In my opinion, the best HK for CCW is a P7PSP.
It is very compact. No safety switch to mess around with. With the P7PSP, it is also impossible to drop the magazine by mistake. If you carry inside the waist pant, the P7PSP does not even have the mag release to rub against your gut (and my gut is a big one).
If you have kids, it is much safer than anything out there. Most kids, specially those who are less than 6 years old can not squeeze the grip hard enough to fire the pistol.
Yes, it only has 7 rounds. However, if you are a civillian, your chance of getting into a gun fight that last more than 7 rounds is less than your change of hitting the lottery.
That is my 2c.
Paven