Gents,
The reason why the USMC is so wedded to the concept of the tiltrotor is indeed range. Not in the traditional sense of invading the USSR, but due to the new "Visions" of Sea Basing and Ship-To-Objective-Manoeuvre (STOM). This argues that, rather than conventional amphib doctrine where you assault a coast, build up combat pwr then strike inland to the enemy centres of gravity you simply fly, direct, to the CoG - thus, the arguement goes, providing shock, dislocation and denial of manoeuvre to the enemy (now removing doctrine bulls**t book from ars*). To go 200 miles plus inland from over the horizon offshore requires a fast(ish), survivable (yet to be proved in the V-22's case) aircraft with good range, hence V-22. But, to deliver the same combat effect in one wave as a Sqn of Ch-53s you're going to need an awful lot of them, or launch the -53s a long time before the V-22s and RV at the IP..
Shytorque, you clearly need to be less subtle in your banter.....