i just have one of these 25 rounders. only used it a couple of times but zero issues. just ordered (well, backordered) another 25 and two 15 rounders (brownell's just had $10 off $100 and free ship).
I have several old C products 10 round 6.8 SPC magazines that work fine with 6.8 SPC. They should work fine with Valkyrie too but won't let you load as long as a PRI.
If you need to load long, Cavity Back Bullets sells windowed PRI mags that allow the longest ammo in an AR short of single loading.
+1 on PRI 6.8 mags. They accept an OAL of 2.300" with a few thousandths to spare. Good if your running 88ELDM because they are 1.24" long and even at 2.3" they are jumping a bit in a SAAMI chamber/throat.
I have 2 - 10 rounders and a 15 rounder. Work and function flawlessly out of the bag.
Thank you all for the input. I’ve ordered some ASC mags to try out. I can’t swallow $35-40 a mag for the PRI’s. Hopefully my inner cheapskate won’t come back to bite me.