I have used the newer style hardware and think that check it is better.
The biggest thing form me was the fact that the spent is harder on the ccm kit.
But don't listen to me, I have just formed my pinion based on comfort over brand.
Heck, my favorite sniper only has ccm springs.
But it also has a custom sft oring seal in the body custom bolt, dp barrel, dye pro frame, ccm feedneck (forgot to add that), rat and phat lowers, Sanchez ivg, xsv Asa, cp reg, check it kit,
And internals are soon to be ion coated.
Sweetspot - 215 psi, 2 1/2 turns in, 3 bags per 48/45 cool fill, decible is the same as a silenced subsonic bullet from a .22 rifle (imagine a phantom with 3/4 the sound.
But it was a very expensive build.