there is really no downside to the blade plug. I have two, one for my Prophecy and one for my liberator, and they are great. They are held in just by the retention screw, which I don't even tighten with a wrench. I just twist it with my fingers till I can't twist it any more. That may not work for everyone but you need not tighten it like you would for a blade because there is zero weight in front of the emitter, so the forces on it are minimal.
this is my little post on the plugs themselves:
http://www.saberforum.com/index.php?topic=6774.0 However, I forgot to mention one other thing I love about these blade plugs. I frequently carry my Prophecy on my belt, at work, around town, just for fun, whatever, and I noticed that the LED module was working it's way closer and closer to the emitter. I had the screws in a little to it wouldn't slip out and potentially break the wires, but I still didn't like that it was being moved around in the hilt so much. The blade plugs hold the module in place so it can't move (depending on the location of the module and your plug it may move just a tad, but that's better than inches).
anyway, that's my two cents. I think they rock and will be getting all future sabers with them.
