My 2c.
+1 to keeping it simple as it is now, agreeing with what Greg expressed above. Big budget builds don't automatically secure a win. Ron's Phaedrus has more (high end, expensive) chrome work than anything else on the forum and it didn't win the first few nominations (in fact I don't know if it has won at all yet, I need to check) despite it winning several trophies at VJMC and other events. Same goes for budget builds, no guaranteed wins. And same for class, there have been 400s that have beat 550s and 750s handily in the past. Campaigning for a build, yours or one you like ins't bad. It takes several posts from Don in various forums to get a decent turn out as it is. There have been months where voting was severely lacking and Don has been doing great keeping the turnout from dwindling. I've nominated and renominated many bikes because I, and possibly many others felt they were done well, but in the end it was what the voters liked best. Tom's beautiful 550 resto was up against my admittedly big budget 750, but I and many others knew it (Tom's 550) deserved to be BOTM and it became one when I renominated it as soon as it became eligible. +1 again, for the current simple set of rules. I've campaigned for Tige's builds in the past because they were a great inspiration for me, and by making more people know about it meant (to me, at least) that more will be inspired by the workmanship. I've campaigned for my own bike when it was nominated, but that wasn't what I built it for. I wanted to build it right the first time so I can keep it on the road, and thankfully that's where its been since its first run. Winning wasn't bad, and if that brought attention to the wealth of info in the build thread from so many great people here, I'm happy.
Nothing is permanent except change, so if there is to be a new way to do this, I agree with Don's point on ambiguity and disputes.