I have gotten 8 hours of screen on time streaming video on my LTEvo, consistently, from day one. And that was without rooting. Normal use goes well over a day. Battery graph screen shots for proof upon request.
The One is doing exceptionally well by all accounts but not quite as good as that, more like an SGS3 or 4 for battery life.
All of which have that extra gig of ram constantly draining power, which I suspect to be the culprit.
As for coming back, hope so. They're about 2 to 1 behind the SGS4 in One sales last I checked.
But selling it faster than the SGS3 for the same performance period last year.
That was a record setter too, so they're not doing badly with that model.
Agree that rooted LTEvo > stock Sammy. Believe that the other comparisons will have as many conflicting votes as there are users.
The multitasking borks for the LTEvo do require root to fix.
I get a lot of stuff running beyond just fine on a stock rooted rom with ram to spare, no AOSP required.