OP: Braided wire springs have advantages "in theory" but I don't think anything has been proven in this application. Bill Geissele has shown his engineering capability and cleverness with many different products so I expect it's a good idea, but until it's proven I'm reserving judgment. The rest of the setup is conventional and it seems like a stiff price for a spring.

A5 discussion: I've been using the A5 system since shortly after it came out, and use it alongside standard carbine setups (most with H or H2 buffers) and standard rifle setups. I also have an H6 buffer that I've done moderate testing with. On the A5 I've only used the A5H2 buffer that comes with the VLTOR kit, not the optional lighter and heavier buffers.

1) Reliability: the A5 has worked OK with everything I've tried, but the A5H2 and the rifle setup don't tame highly overgassed uppers enough for my taste. It does work well with reasonably gassed (typical 16" midlength) and marginal (18" rifle) uppers, but those also work fine with carbine if you're willing to choose the right buffer. You could buy and use the other weight buffers but that adds considerably to the cost of the A5 system, and for someone who already has the full the range of carbine weight buffers it's just too much extra hassle.

2) Recoil: in my use the perceived recoil of the A5 is sometimes better than carbine and sometimes not, but when I have video of my shooting the visible recoil is noticeably less compared to a carbine and H buffer.

3) Value: if you're building a stripped lower, the extra cost of the A5 setup is only $10-20 more than a comparable quality carbine setup (true milspec buffer tube). I think it's a reasonable choice for a new build, depending on the uppers you plan to use. I wouldn't toss an existing carbine buffer system to install an A5.

4) H6: this is supposed to be an alternative to the A5. I've only tested it to a moderate extent and it works fine in that limited testing. I can't comment on exactly how it compares to an A5.

5) Severely overgassed uppers: H3 buffer and quality GI spring or H2 buffer and Springco Blue will tame most. You could try an H3 and Springco Red if the gassing is outrageous, but if it's that bad you should get an adjustable gas block, or just toss the barrel and start over.