I picked up an H&K USP9 this week. My first 9mm.
I've shot lots of 9mm's but never owned one before.
I know, I know I should hang my head in shame.
All funnin' aside, I really like this piece. It has a Jet Funnel (mag funnel that extends the grip 3/8" and then uses 18 round mags instead of the 14 round originals).
The biggest reason I bought it? It came with 7 18 round mags, the last I saw listed for over $65 each.
It has night sights, although the tritium is starting to fade. IThe glow is still visible, but will need to go back to Trijicon for new capsules in a few years.

There are a couple of reasons why I bought this, one is that the recoil spring is light enough that my wife and daughter can rack the slide easily.
The USP9 is destined for duty as home protection, so it must be operable by all of the members of the household.
Operatrion is nice, the DAO trigger is lighter than I expected, maybe due to it reportadly having the Competiton trigger in it? Not having shot one before I couldn't say for certain.
Take-up is long, but the actual trigger pull is pretty light.

As is my custom, I stopped at a buddy's place on the way home and put a few magazine loads through it. I had bought 2 boxes of Magtech hardball, as I didn't have any 9mm at home.
I inmserted the first mag, racked the slide took aim, pressed the trigger and got a very unsettling CLICK! Hhhmmmm, OK, so I waited for a minute with the gun pointed at the target, tried another strike (multi strike capability is nice) and gotr the same click.
Does this thing even work? After ejecting the dud round, all the rest went bang like they are supposed to. Right to POA as a matter of fact.
It seems to be very accurate, but stnding in the 15* cold with 15 mph winds really made it hard to judge for sure.
We'll see when I have a chance to ring it out (probably in Arkansas at CSA).

It's not a revolver, and it has all the appeal of a shovel, but it is a well made and from what I gather a brute strong, durable piece.
I like it!