Hi,
I own a couple of Lee hand primers (the single primer and round primer tray models--haven tried the latest one), and have used the more recent model RCBS hand tool, too. They all work fine, with the RCBS probably being the tougher built model.
That said, I hate those gizmos a lot of presses have with some variant of the flippy floppy thing. And as I load less these days, meaning I'm in no kind of hurry, I use the ram prime tool that goes on top of the press. I have them from Lee and C-H. IF I had to choose one and only one priming method, I'd go with Lee's version of the ram prime tool.
If speed was the criterion, I'd go with the RCBS hand tool. But I've never used a bench mounted tool, so there's still more to learn!
Rick C