Performance comparisons between electric and nitro is a double edge sword.

For equal flight times, nitros are generally more powerful than electrics. But if you don't mind trading shorter flight times, electrics can be setup to outperform nitros. Nitros basically deliver the same power level throughout the flight, and burn the same amount of fuel. With electrics, you can increase the 'fuel' consumption in order to get more power, but sacrifice overall flight times. An electric that outperforms a nitro usually only gets flight times int he 4-5 minute range at best, where Nitros can go a full 7 or 8 minutes on a tank of fuel.

A trip on YouTube searching for T-Rex600 Nitro 3D and T-Rex600 electric 3D will show you the performance level of both machines, and both can kick serious butt! If you are fairly new, you'd most likely run both at a slower pace, and get long flight times on either elec or nitro. The power difference won't be that important for a couple of seasons at best.