I have had great experiences with the canon LiDE scanners, they use a new technology which sources the light from 3 LEDs refracted through a prism rather than using a cold cathode. The advantage os this is that there is no warm up time, and it uses very little power, so is power from the USB cable it connects with - it needs no AC Adapter. Their mac software is easy to use, and I have never had a problem. I Have the canon LiDE 20.
The quality is more than adequate, I mostly scan newspaper and magazine documents, but occasionally use it for photos and it is great!