I know this is an old thread, but I think that perhaps winners should be limited annually, on a rolling year system. Like, for example, if I win ten (six, eight, twelve; this number is a bit arbitrary, but it should be enough so that people can fairly win a few, without getting to the point of excessiveness) weekly review rumbles, then I would be ineligible until one year from the week I won the first rumble.
I just feel like we see so many repeat winners, people who consistently win--which means that they write AMAZING reviews. But, in that same respect, it almost makes it impossible for other newcomers who may have had REALLY GOOD REVIEWS to win, because you've got these powerhouses dominating the rumbles.
Personally, I don't like the rumbles as a concept, but this is just my suggestion on how to, perhaps, level the field a bit for newbies.