Prvi seems to be good brass, but I bought some 7mm Rem. Mag. Prvi that was 14% heavier than Winchester. That could be significant with maximum or near maximum powder charges. I don't know whether their other brass is extra heavy or not.
Holy fu ck, haven't you read through this thread. Winchester brass is thin, the Prvi/PPU is probably not as "extra heavy" as you think... Also another reason to ALWAYS start low and "work up"...