Question on x230 fan-noise

Just received an x230. Everything but the fan noise seem to be up to my rather high expectations. However, I'm wondering, if you've used an x230 and paid some notice to this:

How high was the noise level from the fan? Mine's about 48 decibel when at max speed, about 10 higher than a review indicated. With normal web-browsing the fan spins up to an audible level then goes back again to what I think is off, at an interval.

I've read reviews saying that the fan should be inaudible under daily use and "whisper quiet" when at high speed. Does this match with reality? I does not with mine, but maybe I'm just picky.

I really don't want to send it back for something that might just be my poor interpretation of the reviews and a fear of this being a problem that can become worse.

Do any of you have an experience with this? Thanks!