As far as rotary buffers go I own a DeWalt DW849. It is the best DeWalt model since it has a variable speed dial that adjusts from 1000 up to 3000 rpm's, and the trigger is variable so that I can slowly start spinning the thing instead of a trigger that just turns it on at full set speed.
Its also got a module in it to maintain full speed even under a full load.
I have used the nicest Makita and I like it too. I liked the handle design. It wrapped around the whole top of the machine allowing a user to get a quick hold on it anywhere, unlike mine and others that have a post typw handle that is movable to one side ot the other. The Makita seems lighter and a little smaller but I am not sure.
I know the Milwaukee is a popular machine and whats nice about it is the detachable cord system. I have many Milwaukee tools and the cord system is awesome. The Milwaukee is a heavy machine but I think that kinda is a preference for the user.
John