Well, I find that with some movies I can't use RC (e.g. 'Tinker Tailor Soldier Spy') b/c of the inherent noise/grain that gets ridiculously amplified. Even with RC at 'min'. For that reason, I prefer optical sharpness. Which I can actually get my stopping down the lens (Iris Open Reg; 725, enable 'Auto Limited'). Of course, that doesn't work for 3D, which opens up the lens all the way. Maybe that's why I feel I need excessive RC with 3D (along with some report that 3D on the HW50 is not actually 1080p... which is weird/concerning).
And, wow, motion resolution must be pretty poor on the JVC if you love the Sony... I'm still mildly bothered by motion blur on the HW50. I can see it get better with Dark Frame Insertion, but I feel the latter to be unusable for 24p content due to flicker. But, yes, the motion blur is much better than on an Epson 8350 I briefly owned.
Out of curiosity, are you just subjectively judging 'motion resolution'? I don't know of a good way of measuring it quantitatively with my current equipment.
The grain does get slightly exagerated with RC even at min, but that movie has grain for "artistic" effect, and I would say 90% of movies now a days are very clean with little to no grain. Not sure if you realize this but great optical sharpness also makes grain stand out just as much. I had the benq w5000 which is considered one of the sharpest DLPs out there and it also made grain stick out like a sore thumb. Don't blame the projector for grain which is in the source itself. Now if the projector added grain itself.....that would be a different story. Not a big deal as you can just turn RC off and get decent sharpness with no exagerated grain for problem movies like TTSP.
The Sony is most certainly the best non DLP projector on the market for motion. If the Sony is not good enough for you then the JVC will be unaceptable to you for motion. I play lots of games which is a great way to test for motion res, and I also use some test patterns from a Japenese FPD benchmark disc which includes the infamous hammock scene which completely destroyed older JVC projectors.
Still interested in getting a VW90 quality lens in combination with RC and darbee to see what type of difference a better lens would make with RC.