Actually the plastic inserts are really Delrin. And Delrin needs no lubrication in a slip stick application...such as in the SuperGlide.
So why do they specify WD-40? Because it inhibits rust on the way tubes, and helps protect the powder coated and painted portions of the hitch.
I still cannot understand how the hitch hung up mid way in a 45 deg angle, when going down a highway. But that isn't important. The fact is, it did and it tore things up. Never heard of that before, unless a foreign object gets lodged in the hitch, or lack of maintenance. And I don't think a lack of WD-40 ion your Delrin insert hitch is the problem.
Now on to your question. A manual slider is a real PITA. A Sidewinder is automatic. And pretty foolproof. If the Sidewinder works for you, that is your best choice if you need a shortbed truck. But I would consider a long bed truck, when a truck replacement is needed.
