Okay, now that I understand how a bov/waste gate works i'm not quite as dumb as I was yesterday.
However:
For Honda's mystical b07a DOHC VTEC engine which, unboosted moves 100 cf/m @ 7600 rpms. When you add the 14g turbo to it which @ 14.7 psi moves 200 cf/m(lets pretend) and set the wastegate or whatever to 14.7 psi, the engine is getting almost exactly twice as much air (ignoring loss caused by friction or constriction or whatever), hence making twice as much torque.
Now, when you strap that big ass t88 on that engine and set the wastegate to 14.7 psi you are still pushing 200 cf/m into that engine and still making only twice as much torque. the only difference is you have a ton of lag, which makes it so you dont see the power in every day driving, and you lose a lot of energy (horsepower) turning a turbo which you are only using to 40 percent capacity.
above is why I said this:
However 10psi of air at a given temperature at the map sensor on a given engine at given RPM at full throttle from a 14g and a t88 will make the same amount of horsepower.
Now, when you switch over to honda's mystical b11a DOHC VTEC engine which moves 150 cf/m @ 7600 rpm, you will get more power out of the t88 than the 14g in the high end, because the t88 is still capable of pushing the full 14.7 psi (now equalling 300 cf/m, which is 60 pecent capacity), while the 14g is only able to maintain just under 5 psi @ full throttle @ 7600 rpms...even though the wastegate is set to 14.7, its only running at 5 psi, and only making 1.3x more peak torque than stock, while the t88 is still making a full 100 pecent increase.
In a situation like the one above, the t88 is still too big, and the 14g is too small, so you would want to go and get a t3/t4 or something which moves 300 cf/m @ 14.7 psi. Now what is going to be the difference in HP between the two? The t3/t4 will be a lot better for daily driving, and will actually be faster than the t88, because of less energy being put into turning the turbo. The ONLY way the t88 would be faster on this setup, is if you either set the wastegate to a higher pressure, or increase the displacement/rpms of the engine.
So, the only time my original, now very flamed, post is NOT true is if one of the turbos is too small to push the cf/ms required by the engine @ 10 psi. The post is ALWAYS true provided that the 10 psi is being read at the MAP sensor.