If you are going to do a few sheets of 4x5, the HP combi tanks are easy to use, although I never put more than 4 sheets in one, as I don't trust that they might adhere to the next sheet. SS tanks and hangers are pretty fool proof if you follow the advice given about lowering and raising. There are pros who can't do it, but most of us don't have any problems.
That said, unless you are using highly dilute developers as one shot, or replenishing, the rotary tanks use less developer. I never did like them, but each to his own.