I'm not saying that the Perun doesn't work. It seems to be a perfectly good holster. Rather, my gripes with the Perun are threefold, compared to Raven's now-discontinued Phantom holster:
1) Cheaper material than before. They went with an injection-molded, folded plastic design, instead of the previous riveted vacuum-formed kydex.
2) Significantly fewer handgun/light options. You used to be able to get a Phantom for just about any handgun and most major lights. I have Phantoms for every one of my carry setups. With the Perun, unless you're carrying a Glock, P320, or M&P, you're SOL. And only the Glock is available with weaponlights.
3) The Phantom had a wide variety of different belt attachments available. Everything from OWB loops to OWB snaps to OWB wings to IWB clips to IWB loops to IWB struts to offset IWB struts, in a variety of belt sizes. The Perun is only available with 1.5" OWB loops, and they just recently added the option to purchase additional OWB snaps. I use a 1.75" belt, and prefer the OWB pancake wings, so I'm SOL.
I understand why they'd do it from a business perspective (cheaper/easier/faster to produce, with a distinctive design that sets them apart from the new glut of copycat Kydex holster makers), but the fact is that Raven went from offering extremely high quality custom kydex holsters with a huge variety of handguns and mounting options, to cookie-cutter mass-produced injection-molded holsters with few options.
Good for business, since they can now crank out holsters more quickly with a bigger profit margin, but not so good for customers.