Just tested these on the morning SFO-EWR on the 773.

I would say overall the legroom is great, but doesn't really improve on the passenger experience that much if you're already comfortable with E+ legroom (legroom adheres to the law of diminishing returns IMO). Recline is the best attribute - as someone who sleeps poorly in regular E, I found myself more comfortable and probably slept longer than I would've otherwise with regular E recline.

The footrest is poor and actively detracts from comfort unless you have strangely proportioned legs that can actually utilize them. Seat comfort is negligible compared to regular E. The screen is OK but nothing special if you're used to using iPads for IFE anyways.

I agree with the poster who said that they will not pay for these seats above a marginal amount. I can see couples willing to pony up for the 2 seat configuration on the sides. Since this is United, I don't expect the soft product (food, etc) enhancements to move the needle much either way. If I'm traveling INTL, it's lie flat business or I'll just suck it up in regular E.