Sounds like a promising formula for a normal topic, but I think it might fail on some enthusiastic but not flaming topics. The feedback topic on a new release of a popular web service for example. Large numbers of people who want to chime in with what they love, hate, or is buggy all at once.
Of course, some of them will be flaming hate-its given the nature of so many people reacting to change, but it needn’t be many for that to get gummed up quickly.
This option seems pretty sound though.