That .50 barrel looks ridiculous, like sticking a pipe cleaner to the front of your gun.
.50 cal for girls, .68 for real men, rarrrr
Personally, until I see an unbiased side-by-side comparison between .50 and .68, I'm not going to believe any of the hype that's being generated by GiMilSim et al.
Sensible move by Planet as it means that people can keep buying PE markers knowing that their investment is protected - even if it does make their uber-light markers heavier. I also doubt if a drop-in kit will function as well as a custom designed .50 marker, as you're not going to have the same fine tolerances with multiple press-fit parts. New, longer detents will be needed and I wonder if there are eye issues if existing board logic is looking for a specific size projectile to transit the breech.