The big difference between the USP and the P2000 is that the P2000 has different grips, and a ambi slide release. Much like the old Walther P88.
The P2000 also comes with the HK LEM trigger, like you can get on the USP compacts. If you dislike the LEM trigger, you can buy a P2000 V3, which has DA/SA with decock, and no safety.
I think the HK P2000 is a great handgun. If you are a left hand shooter I think the P2000 is one of the best left hand guns on the market today. But if you are cheap like me, the USP compact can be found for $500 and less. The cheapest P2000 I have ever found was $675.
If you like the 45, and want to carry the 45 then you should look at the HK USPC. Or the SIG 245. The Hk USP .45C feels better to me than the SIG 245. But that is just me.
There as been a lot of HK fans who would like to see a P2000 in .45 but it looks like we won't see one for a long time. HK is building a new 45 for the German Army, the pics can be found at HKpro.com and it looks like a combo of a USP and P2000
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