I personally don't have a 5er, but we camp with friends and family that do. Two of them have manual sliders and one has an auto slider (dont know what brand).
The guys with the manual units very rarely use the slide feature, and the hitch can be lifted out by 1 person.
The auto slide on the other hand is pretty heavy, he actually uses his Bobcat to load it into his truck and still has to wrestle with it a fair amount to get it into the rails. Also another thing about the auto slider that he has is that it can be kind of a PITA to hook up to, his has a steel block on the pin box that has to engage into the hitch along with the 5ers king pin. I know that he has had some issues on smaller, unlevel camp sites in county parks getting everything lined up and hooked up.
If it were me, I would buy the manual slider. And actually I may be buying one, since my boss is selling his truck and taking the 5er hitch out, so I may just buy it incase I buy a 5er in the future.