My intent isn't to poke fingers in eyes, yet that is how it seems to be taken.
Many folks have commented on size. As both of you point out, it is that size because of the initial design parameters established by USMC. Had AFSOC been in a position to begin the program, it would have been a different size.
As mentioned, AFSOC has no money to pursue acquisition of aircraft & even if they did, the small numbers would dictate even higher per-unit costs. The MFP-11 money used by SOCOM to modify service items (vehicles, aircraft, weapons, etc.) means that AFSOC takes standard items (C-130) & makes special mission variants (MC-130, AC-130, etc.). So we adapt the MV-22 to CV-22 & accept compromises. That these compromises, which are out of AFSOC's control, are now points of contention with Osprey critics seems to be lost on some...
My assertation that USAF should do the acquisition lies with experience & specialty. If it were a rotary asset shared jointly, I would say USA has the lead. Anything on the water, USN/USMC. Fixed wing, USAF. Osprey is unique - current DoD VTOL experience does indeed lie with USMC Harrier program. Special Mission experience most definitely lies in SOCOM & the air component of SOCOM is AFSOC. The Osprey is more than just VTOL & I would argue that Harrier VTOL is apples & oranges with Osprey VTOL & aligns more with special mission. But SOCOM doesn't do major acquisition, so we're back to square one - which service? I stand by my guns that USAF should do acquisition of Osprey & it is precisely the lack of experience in major aircraft acquisition by USMC that has caused some of the problems - put your hackles back down, this isn't a slam on USMC.
I'm sure there would be many concerns over big user (USMC) vs small user (USAF) with oversight/control, but that, I believe, is easily rectified with Joint acquisition & carefully delineated acquisition requirements. Maybe I'm too optimistic...
As for unconventional aircraft & vertical lift - as soon as you mention the term unconventional, we need to start defining things. My definition (all subject to my own personal biases) is SOCOM = unconventional. I'm sure yours is quite different. Such is the nature of discussions - we each enter with our own personal biases colored by our experiences. There is very little that is right/wrong, black/white, rather, best for a given situation - hence our different points of view. It'd be much simpler, yet very boring, if we all thought exactly the same way!
Of course, all of this would be much easier over a beer...