After buying the HK45, I bought the HK45C for CC (both are SA/DA V1). Carried it for about a year or so and decided I wanted a subcompact, so I brought home a P2000sk LEM and it's been my EDC for the last six years. I don't carry AIWB, so I can't offer any guidance about that.
Here's the size comparison:
The compact 45 caliber line of H&Ks are arguably the best production 45 compact pistols on the market. In my opinion, the P2000sk is the best subcompact pistol on the market today.
As is the case with just about everything else, it all boils down to personal preferences and likes.