potentialgeek - 9:40 am on Jan 8, 2012 (gmt 0)
I think you only have to worry about BR or TOP when it's extremely bad. I believe that's the only time Google would take it as a valid signal. When a signal is inherently noisy, it only makes sense to value it when it's so extreme it's not that noisy.
Your site: BR - 95%
Your competitor's site - 10%
P.S. If you want to check your competitors' bounce rate go to Alexa.