I like that these choices are moving to piston systems. I built my last impingement gun three years ago and haven't built anything but piston guns since. I consider the Osprey to be the best/most reliable, and the Adams Arms to be the most versatile. I've built and tested both extensively, until ammo got cost prohibitive.
To be honest I don’t know that much about guns. I only owned a .270, 30.06, several shotguns—pump and single shot, a .22 semi-automatic rifle and a 9mm pistol. Owned. I like reading about them, but couldn’t make any type of knowledgeable statement on the types in this article.