I had the Black Peral VW60, not the VW50 and most of the lower JVC lines, from RS1 to RS20. I've the chance to upgrade to a RS40B this week but decided not to.
Yes, there is motion blue but that is not critical to me; neither is 3D. What is important to me is contrast and black level, especially in viewing Sci-fi or dark movies. Though the Sony is very competent and has very natural colors, but the lack of dynamic iris in the JVC really separates it from the crowd.
I'm considering getting the Darbee digital video processor to improve sharpness and contrast further. You may want to get in line to order one for $269 from this forum, a cheaper alternative.
The RS40B will overwhelm you in terms of brightness and contrast, if you do go for it. One more thing in Sony's favor, the JVC lamp is usually good for 2,000 hours and is just as expensive as the Sony.