I can't speak to the 50w, however I never thought I would need 100 and I see myself going beyond that in the next few months. But I'm crazy with stuff like this. As for the loose 510, that was only in the review batch. It is fixed in the original. The plus has double the magnets on the back and no screw holes, though the original is fine without screws. It also has a spring loaded 510 instead of the adjustable one which, if it works well, is very nice.