Vizio P Series 4K TV and the Roamio Pro

I'm in the market for a new TV and I'm seriously considering picking up the VIZIO P602ui-B3 60-Inch 4K Ultra HD Smart LED HDTV (what a mouthful!)... At $1,699 it's in my budget, and while there isn't a whole lot of 4K content available at this point, I plan to own this TV for at least the next 5 years and there will be more content as time goes by.



Obviously I won't be able to watch 4K TV by way of the Roamio on the Vizio until TiVo’s coming line of Ultra HD/4K-capable set-top boxes become available, which could be a while...



But one thing I'd appreciate all of your collective input on is what I can expect in terms of quality when viewing regular 1080p/i HD programming via my Roamio Pro (along with my crappy Time Warner cable cards and tuning adapter)? To the best of my understanding, as things are right now I'm only able to view 1080i on my Sharp Aquos 60-Inch TV. How's that going to look on the Vizio? Will it even work properly? Will there be overscan fuzzy/static lines around the edges of the display? Will the Vizio attempt upscaling my measly 1080i video source into something it just ain't?



I guess the main thing I want to know is will I be able to watch Cable TV programming at the same (*or better) quality than I am currently watching it, or will it somehow be worse/problematic?



Any feedback would be greatly appreciated... Thanks!