I've got the 20K with slider. Have used it 2 seasons so far and just put it back in the truck yesterday for this up-coming season. The head is a one person lift, but the body and slider is a two person job, at least for me it is :) So I get my son in-law to help since I store it for the winter in his garage anyway.
I think it's a great hitch. Very positive lock-up and easy to to visually check when it is locked up. Have fount it smooth on the road (ie: no chucking) except in some really nasty spots that I'm sure would shake anybody's setup.
As far as the slider goes, I use it occasionally... rather be safe than sorry kind of approach. I pull a 2005 Travelaire (9500 lbs) and it isn't as 'contoured' on the front corners as some of the newer models seem to be.
Highly recommend the Curt.