Less foot-feed does not equate to less fuel with the electronic mods. Like said above, they lie to the PCM. The accelerator pedal is electronic, and has NO direct correlation to actual throttle position or fueling. This is why you had the experience with the 1/2 throttle take-off. Earlier fuel is earlier boost, resulting in earlier power. You should never have any significant amount of black smoke with any of the available power mods at low settings. If you do, something is wrong (like an overdue air filter or poorly positioned or dirty MAF). Most of them produce very little smoke, even at moderate to higher levels. More power is more fuel. There's no way around that fact. If you are using more power, you are using more fuel. The key is using (and not using) that extra fuel at the right time. Also, spending money on the mods to get better fuel economy will rarely ever return your investment. We should always consider any economy improvement a bonus to the extra power. If you get it, great. If not, then it's just "normal".