Hi Gary,
I forgot to mention one important point. Consistency. With fuel vapor, fresh fuel vaporised better compared to older fuel. I use variable valve to inject fuel vapor into air intake. With fresh fuel, I need to allow tiny amount of air into fuel bubbler to get vaporize. After few minutes, I need to adjust again to allow even more air into fuel bubbler. This shows the energy content becomes lesser over the period.
While with water/methanol, so far I don't see much changes in the energy content over period of time. With water/methanol, I don't use variable valve to control the amount of vapor to enter air intake or intake manifold (vacuum). I didn't do extensive test with water/methanol mix but if someone has done this experiment may contribute your findings.
It makes sense why some people uses fuel drops or fuel injecting for fuel vapor technology. Everytime new fresh fuel enters into vaporiser canister so the consistency can be maintained.