RE: Tuning nightmare
About doing upgrades to the drive train, My personal opinion is don't do anything until stuff starts to break. Once things start to break is plenty of time to upgrade. I cannot see dumping a butt load of cash into the drive train because stuff might break. But that's just me and I'm a big fan of "if it ain't broke, don't fix it" so you can take that for what it's worth.
I've never owned a 3.3 but my 2.5's have all been great little engines. IMHO the best all around engine for the Maxx was the OS .18TM but since it's not made anymore my next engine will probably be the Picco.