A5 system works better - VLTOR A5 Specialty Buffer

I have a BCM lower with their Mk2 buffer system, it came with a T0 buffer. Bought the VLTOR A5H4 to experiment with weights. Landed on H2 or T2. The difference in the 2 brands is the spring size under the rubber bumper but the functionality is the same. A SOLGW 13.7 midlength gas shoots super smooth with the A5H2 and a 15% extra power spring.