I use it on WIndows.
Had some issues after upgrading this past week to the latest published version.
Artwork for .wav files stopped loading. I had to upgrade to a more recent beta release to get this new bug fixed.
Also they dropped the handheld skin in recent versions, which made my Windows Mobile browser less useful as a controller. I found a blog post where that provided the files though and once i put these in teh right directory, the handheld skin worked again, however it appears that it is being dropped from support which I think is a bad decision in that I find it fills a more useful niche in the controller device world than the classic skin that was retained. The classic skin is inferior to the default and handheld skin IMHO. standard skin is more functional on typical pc browsers and hand held same on handheld device browsers.
Of course, Iphones and android devices are supported with the new controller program you can install so that is probably the way to go for those newer devices.
Apple and PC covers most users so I would expect both to be solid platforms in general, more so than Linus, which must be a minority platform I suspect.
I was a bit taken back though with the inconsistencies and on off changes in the latest release though, and I suspect that this may be the case on all platforms.
The Squeezebox server has been mostly very reliable to date. I hope these recent issues are just a blip and not some new pattern that worsens over time. NOthing beats good QC! I'd say the regression testing was lacking with this latest server version release.
I am pretty computer savy yet it took me several hours to work through these issues and get my library back to the state it was prior. A novice would probably have had little chance and ended up with a broken server and a lot more angst.