with the EA mod, you can use different batts and put whatever you want on it. With the QZI, you're limited to the small 18350s and will need to change batts much more often. If you want a hybrid, wait till the ihybrid pure comes out in the next few weeks.
edit.. I just saw where the QZI has an optional 510 top cap, neat. I'd still go for the EA though. But it basically comes down to what exactly you want.. bottom button, batt life/being able to use different batt sizes. I haven't heard much about the QZI as far as performance goes but I would imagine it would be fine.