I don't carry my e-ink readers around; I already carry around a smartphone and a tablet. Also, if I carry around my ebook, then it won't waiting for me at home. (I'm a bit lazy and like my book to Always Be There, rather than sitting down to read and then realizing I'd left my book Somewhere Else and have to get up and go figure out where Somewhere Else is.
)
I don't use my e-ink readers less; I use it just as much as I always have. I am, however, starting to use my tablet more for reading when I'm away from home both because I've stopped carrying around knitting and also because I bought a NOOK book and I am using NOOK apps to read it.