All I can say is that it's worth trying the Saft option to get a feel for it first-hand. It's a matter of the subtle tactile experience -- and the fact that it works on any Mac.
It's not necessarily the end-all feature addition for TextMate, I just thought it worthy of consideration. And it really is different than 2-finger scrolling. My primary Mac is a 15" PB 1.67 -- I know what 2-finger scrolling feels like, and it is a different experience as it currently stands.