I use my 28's for both,but knowing my 7B-sst(which I use for my centre)is no slouch,
If I could get the speakers that I'd be happy with for a long time,then I'd probably go with the 7's.
Butttt I don't have to,so I'll probably upgrade my 7sst to a 28(just cause).
Whatever you think will make YOU happy,THAT's THE TICKET

.