I think it's ok for use in an office, but for my room it's too noisy. I just put the machine into reduced mode which should run on 1Ghz. While typing this the cpu is around 50C and the fan kicks in again.
My friend has a ibm T42 laptop running 7/24 and never hears the fan turning on.
Now I'm waiting for apple to arrange a collection. I would say the after-sale service of apple is great. No hassle at all. The os x is also a great piece of software. But their hardware is not.
Well, I'm glad at least some of your experience is positive. One note on the power-saving modes - they tend to act as a 'suggestion' to the system - under periods of high stress (i.e. exporting h.264 video) the power savings features still allow the processor to bump back up to full usage, whether you have it set on auto or reduced.
Again, the fan noise is pretty common on 12" Powerbooks though - you might've gotten a particularly hot sample, but they're just not as quiet as the 15" Powerbooks. (For comparison, I leave my 1Ghz PB on 'highest' (as it's my main work machine), and only hear my fans ramp up above a whisper under extended gaming, or if I'm doing big chunks of video.
I assume Apple has done some troubleshooting with you?