Nice. I have a Blacklist TiN barrel spec'd out for one of my Poly 80 builds. It's a lot of fun just mapping out the parts for these frames. I got burned out on doing the same with AR's...there are so many AR companies making interesting parts..rails, stocks, triggers, lights, muzzle devices, optics, color combos not to mention all the subcategories with calibers, SBRs, retro, "mission" specific builds, pistol builds etc and hard to keep up with all the latest and greatest that I decided to take a break from ARs and jump on the custom Glock bandwagon. It's kinda the same deal with these Poly 80 builds but on a somewhat smaller scale and it's new to me so having fun learning and building. Still lots of aftermarket options but sticking with the G19 frame doesn't seem as overwhelming...pick a slide, barrel, sights, trigger, customize with some colors, maybe add a magwell, RMR etc just more manageable than the AR scene right now.
This is why I'm doing it too, I have way to many ARs so I wanted something different to tinker with. So I will soon have way too many Glock pistols.......LOL