I also have a Demco as shown in an above post. One of it's advantage is that it doesn't have an air bag, therefore you don't have to maintain air pressure or worry about replacing an air bag at some furure date.
If you analize the various air, Mor Ride etc. hitches, some of them dampen the up/down motion better and some of them dampen the "chucking" fore/aft motion better. None of them dampen in all 4 directions equally. So maybe you should figure which motion you object to most. Check out ALL of the websites.
Demco has a very good video that shows its damping action. I persanally think that it comes as close to dampimg all 4 directions as any of them.