E75 bears a business series camera just like E71. Picture isn't quite as sharp and there's always some noise/blur even in the day light photography, won't talk about the night really coz their LED flash is not very hopefully helpful.
N82's camera is already above its class. Better than N95 and other lot in indoor and night photography coz it comes with Xenon flash that simply makes mince meat out of LED/dual-LED things. It also bundles Carl Zeiss lens, 5MP resolution, image stabilization of which E75 is a bit of shy.