My store is in the middle of rolling out E2E in softlines and market. I can't speak much about how market is doing but it seems to be going alright for SL. We were already doing the majority of our freight dayside anyway, so all that changed is we got a couple team members trained in price change and instocks (who will focus on those entirely, instead of the everyone does everything approach other stores seem to have taken). Instocks was pretty much neglected entirely beforehand so that can only improve, and most non-hanging freight is usually finished by a couple of people who come in at 4am, so most team members don't even see it. Frankly, this hasn't felt like the huge, terrible overhaul that it was made out to be - for some tms, there's nothing they do any different.
I especially like that there's more control and accountability in the department. When something is done wrong, there's no more complaining about overnight or a different team- we can actually figure out who's making the mistake and teach them how to do it correctly.
For those who are struggling, I think a factor to consider is just basic speed - the more you do something, the faster you get at it. So, no, these newly trained team members can't backstock as quickly as BR team members who have been doing it for a long time. But there's hope that they will get there with time and practice.