If you are shooting full power loads, then the .308 spring might be a way to go. The AR-15 spring, as directly compared to a standard buffer with a stock spring and a +25% spring...I like the standard buffer and +25% spring more. I typically take weight out of my AR-15 buffers, but I am running a slightly heavier sealed buffer on my .450 BM now. One nice thing about the JP SCS is the capture which allows you to run with no buffer pin. I've gone to running all of my ARs with no pin anyway, so for me it's not a huge deal.
So now that I have figured out that most of my WOW! was due to the EXTREMELY heavy (and wrong) buffer spring, my enthusiasm has waned. If I were going to tell someone to spend $100 to $150 to take out recoil, it would be an adjustable gas block and comp before messing with the buffer/spring assembly or the carrier.