The big issue I have with the 'upcoming' Vizios is that of screen sizes.
With the R series they go from 65" to 120" and nothing in-between! Hello? How many homes will have the wall space for a 120" screen. Add to that, many people like myself, want a larger screen size (75"-85") but not gargantuan to fully enjoy the benefits of 4K.
So for me that pretty much eliminates the "R" series and leaves the "P" series. As to whether the P series will be as good as sets from Sony & Samsung, remains to be seen. More importantly, even there, we're talking about a max screen size of 70". So little interest from me for the P series either.