my 2 cents...

first off if you search you will find the topic covered often.

This is the conclusion I have come to after reading a lot of posts about the VAFC.

They are not useless, just limited. The VAFC is something for people who dont plan on doing a major build, basicly if you only plan on I/H/E then a VAFC can give you small gains. Idaho Speed Center here in Boise Idaho claims the VAFC will typicly gain 10-12 hp after dyno tuning with I/H/E. If you plan on doing a larger build, say turbo, cams etc., then it would indeed be a waste of money. Why? Because the VAFC does not adjust spark/timing. It can only adjust fuel trims (air to fuel ratio), and the VTEC crossover, along with having some monitering tools. When or if you get a VAFC, you must have your car dyno tuned to see where how your cars power band looks and try to smooth it out with the VAFC's "fuel correction". I have been told (havent seen for myself), typicly our cars run too rich when we put a short ram or CAI installed, but just forget about that, cause what matters is what the dyno tells you. Adjusting the fuel and saving the settings while on the dyno is where you will get your gains.
As for lowering the x over point. I have heard people say that "honda placed the x-over point where it should be for optimal performance" I have also been told that a "properly working vtec" does not have THAT much of a kick. On that note, why did Honda make the x-over point on the new RSX higher to give it a bigger kick instead of optimal performance. OK so here is my point. I think after you do get I/H/E and VAFC dyno tuned lowering the x-over point A WEEEEEE BIT may help. I have seen a lot of people lower the x-over point to 4800 rpm, and these are people who know what they're doing, not just some dumb kid who got a VAFC and dropped the x-over to 3000 rpm.

once again, they are useless if your planning a major build, not useless for mild builds...if you have a mild build and get a rom editor, I find that silly as well.