I'm trying to get my three-finger tap to middle-click functionality in Mountain Lion since MiddleClick seems to have been broken in the upgrade. However, in order to let BTT react to tap gestures, "Tap to click" has to be unchecked in the Trackpad preferences panel.
But by doing this, you remove the ability to either one- or two-finger tap on content to interact with it.
I'm 99.9% certain I checked everywhere in BTT's settings, but I cannot for the life of me figure out where to find the options for those (though single-finger gestures do allow for taps in quadrants, I don't like having to tap in specific places on the trackpad—it's more convenient as it's implemented in OS X).
Edit: I'm open to alternative solutions, so long as it's not MagicPrefs. At least on my machine, that app seems to make the trackpad pretty wonky with the sensitivity.