I've got the 80GB model with the 4 USB ports, all the card reader slots and the PS2 backwards emulation (no chip, just software emulation).
If I just have it on and I'm using the XMB, it's dead silent. If I watch a Blu-ray, it'll be silent for a few minutes, but the then the fan will kick on for the remainder of the movie. Depending on the ambient temp, it'll either be the low or the medium fan level.
I don't believe I've ever heard it go to the high fan level, but the fan certainly gets up to the medium setting sometimes with games.
For Blu-ray movies, I can definitely hear the fan going during anything but a really loud part of the movie. It isn't terrible, but it's certainly there and quietly audible.
I keep my apartment cool and the PS3 is in an open TV rack (very good air access on all sides). So I could easily imagine the fan coming on sooner or going to a higher speed if its in a more enclosed rack or in a warmer room.
It is certainly not silent for Blu-ray playback, which is why I would consider getting a stand-alone player. But I actually plan to eventually have all of my components in a centralized "closet" type setup, in which case, fan noise won't be an issue anymore
It's still a darn good Blu-ray player in every other aspect - loads fast, always has the latest updates, navigates BD-Live quickly, decodes all HD Audio codecs - and I'm fine with either using the Bluetooth remote or getting the Harmony adapter, so the fan noise really is the only mark that I have against it. That noise is liveable for now and won't be an issue when I move it
