I doubt they'll ever replace treestands but for me they seem at least as productive if not slightly moreso.
I took all 5 of my deer this past year from pop ups & 8 out of 11 the year before.
I set them up a couple weeks before the season & leave them there. Out of those 8 deer year before last 6 were doubles. Once they accept the blind as part of their environment they dont understand what happened when you whack one out of a group. They look around for a few minutes & settle down as long as you dont blow it.

I like sitting in a tree better personally because I can see more area but I cant argue with sucess.