Though I didn't have any issues with Polish military surplus in terms of split case necks, I did notice about 20% of the Romanian milsurp has split necks. I have yet to notice any differences between them and those without.
About PPU being mild, I found that to be the case as well. It's one of the reasons I stocked up on cheap Yugoslavian military surplus (PPU); I don't want to beat up my M57s when plinking. If I want to impress someone with the blast and flash, I'll break out the S&B commercial fodder.