I popped xcpuscaler on (the trial version) and d-ham that puppy sucks power - looks to draw 200ma - 220ma *all the time the unit is "on" - minimum. There was a nice detailed post over at pdaphonehome that covered a lot more use cases, I can dig it up if anyone cares, but I can say for sure I see the same thing.
Using autostep (which still lunches mine if I power off and back on with it running) I only see a higher draw when something is being done (since it's ramping up to 520mhz vs 416) but draw drops back to normal resting draw between taps. Still was able to burn 10% of an OEM battery in 15 minutes of surfing. Fast surfing for sure, but very bad for the battery.
I would guess you're using 25-30% more ma... or cutting your battery life by the same amount, using autostep - just wish it didn't lock my phone comming out of standby
With xcpuscaler, you're using 100% more of the normal ma draw or worse (ouch!) or cutting battery life in half, or thereabouts. I don't *think* you can get twice as much done in half the time just because its faster.
That said, with either of these, while surfing, the delay between "locating..." and "opening..." in PIE is really not there at all. Even faster then on AC when the cpu speedstep is off. It just goes *pop*. I think the native speedstep is a bit too agressive in stepping down, so it gets stuck with a 100mhz speed when it's trying to do actual work.