Can't tell you about the other two, but I reviewed the P2000SK for Women and Guns earlier this year.
The gun managed to feel both solid and lightweight, not an easy job for the designers.
I don't like the mag release, but it could be that I'm persnickety. I couldn't activate it with one finger or one thumb -- it took kind of a downward pinch to get the mag to drop for me. That could have been just a stiff spring, but the release tends to seesaw and catch on the other side, so I dunno.
I loved the LEM trigger. It is light, smooth, and has an amazingly short reset for quick follow up shots. Heard a rumor that H&K will be offering P2000SK's with traditional DA/SA triggers as well as with LEM triggers; if so, I'd opt for the LEM trigger every time.
I liked the option of changing the grip panels to fit different sized hands. To my mind, an essentially unchangeable grip size is the biggest drawback of polymer framed guns, so it was nice to see that H&K has figured out a solution for that one.
No problems with reliability or quality of course.
Love that it can be easily used left handed, none of this "mostly ambidextrous" crap that has people doing all sorts of odd funky things to force a really incompatible design to work for them. Wonderful gun for learning to shoot with either hand, or to use to teach a lefty if you yourself are a righty -- everything is really-and-truly the same.
pax