The Kelderman setup is nice if all you need is a simple Class IV 2" receiver. That won't work for me... I have a Torklift Superhitch so I can tow with my Lance camper.
The Ridetech one looks very interesting, but it's $1600 and frankly, it looks cheap.
The Fleetco one is supposed to work on 4x4's despite what their website says (I have an email from Fleetco saying so and including a part number for the Dodge 4x4 system), but it's $2000. It's also WAAAAY beefier than the Ridetech.
Before I spent $2k on the Fleetco, I decided to try the Roadmaster Active Suspension. I have it sitting here and with luck, I'll install it this weekend. Installation looks beyond easy... probably two hours max, taking my time... and most of that will be spent just jacking the truck up with my one good arm (broken collarbone now at eight weeks healing time, so it still slows me down).
If the Roadmaster setup doesn't make the thing ride significantly better, then it'll be time to get me a Fleetco setup once I can scrape up the cash.
Rob