I have it, only halfway through it. Taking it kinda slow cause I am not a one sitting kind of guy. I am only comparing the Unimog to the Motorized Excavator and 4x4 Crawler that I have finished already. The Unimog is the largest technic vehicle ever. The pneumatic system is pretty neat and there is a bunch of functions for the arm using a switch system. The suspension system is pretty good when you push the unimog over some obstacle. If you don't have a motorized excavator, I would get that over the Unimog because the gear system is really complicated, and that it could be out of production soon.
The only thing it lacks is that it is not remote controlled, which is why I am taking it slowly. I found some tips on eurobricks forum to add a few more motors and remote control it, so I am in the process of customizing it. The 4x4 Crawler also helps as a baseline since they have similar suspension system(minus the motors).
Does anyone know if there are any upcoming sales that include technic sets? The previous TRU sales excluded them.