I do find myself playing my T6 premiums a lot more than T8 counterparts. Don't remember the last time I loaded a premium round in either my T-34-85M, Bromwell or Type 64 although latter is a recent addition.
I play the Skorpion here and there too as frankly it's a mildly OP tank in which I haven't fired a single premium round so far either. Rest are just gathering dust at T8 as they lack penetration with a bunch of ridiculously armoured vehicles getting added recently.
Only issue I have is that I feel guilty playing T5 and below as it feels a little seal club like.