Bummed with my new Hacker!
I was running a two cell E-tec with my speed 300 and the performance was ok for hovering, but that's about it. The Pixie could have handled the current of a 3 cell but the BEC would have been pretty taxed at that voltage with four servos and a gyro, so I never tried it. My AUW without batteries is 204 grams. My 8 cell NiMH battery packs come in at about 98 grams, and my 3 cell E-tec comes in at about 74 grams.
After further testing, I ultimately concluded that the performance with the Hacker/Phoenix and an 8 Cell NiMH pack was about the same as the speed 300 in terms of power, and a bit better in terms of duration. Turns out that the main advantage of going with the Hacker is the ability to safely run the higher voltage 3 cell li-poly packs, and of course, Hackers don't wear out like a speed 300.