i currently have the et5 as well as an older prem 16ls2
had the pv10a, pv12 and 14 in the (quite distant) past
the current et6 is an upgrade from the just prior gen et3... which was not a great sounding unit for the money - the et5 was a huge step up in sq
i am sure jeff and the guys at cj have improved the et6 quite a bit as a result of the relatively poor performance of the et3... i have not heard it... but i would suspect the et6 would be substantially better than a many many gens old pv11, caps upgraded or not... the pv11 would be substantially more honey colored, less resolving less impactful on transients, throwing a more muddled stage