I don't much feel like dropping the paperwork and money on an entirely new rifle vs having a cool customization option.
Crossing fingers it's possible to buy the barrel on its own.
I have a Gen 2 MagPull P-Mag and a Gen 3. I can't recall which one came with the rifle (I *believe* it was the Gen 2, but I bought the second one from my LGS while I was there picking it up and don't recall anymore.)
I haven't been tracking if the issues are specific to one or the other.
Managed to get my hands on a Hellion about two months ago and finally got the chance to start shooting it.
I've run into a few failure-to-feed or stovepipe issues, though. Sometimes have to pull the charging handle back and shake the round loose because two rounds are trying to load at once or...