I don't like this thread because it presents the question wrongly and with confusing options. "Percent to change tiers" isn't the same thing as "percent to declare uber", which is what we are talking about in the other thread. The former (what this thread is about) places value on the status quo, and the latter doesn't. If you intended this thread as a supplement to mine, the question is very problematic. (Additionally, the poll shouldn't be private.)
In addition to those problems, I would first like to establish that the simple majority is not widely supported. There's no reason we need to decide on a particular ratio at this point, and also no reason to exclude other options. My formulation of the issues is better.