If you're making a big scale rig, I would go with a clod. If you're making a 2.2 crawler, go with a shafty.
I made my first crawler, Bergsteiger, about a year ago:

It was alright, but the rear links were too long causing the rear gearbox to get stuck on rocks.
Then, I made a TLT:

But, I cut corners, so consequently, it sucked.
Then, I made Bergsteiger Zweite, which used the same axles as the first one, but had some major mods (behind the axle steering, new chassis, cut tires):

It worked pretty good, but the motors were crap, so I sold it to get a MT2. I kinda regret it, but I know I'll get another crawler eventually.