I haven't, but I recently tried the overcommit gem which uses rubocop and I kind of like it so far..
https://github.com/causes/overcommit/blob/master/lib/overcommit/plugins/pre_commit/ruby_style.rb#L9
What would you be looking for to run it on every commit? On its own, I think metric_fu would be too slow to run on every commit. It's strength, I think is looking at trends. Also, right now it saves data daily, not on every run, (i.e. YYYYMMDD, not YYYMMDDSS) so you wouldn't easily benefit from multiple runs a day.
It's certainly worth thinking about, though.