I bought my daily-driver Mac, a mini, pretty much when the PowerPC mini was released. I was tempted beyond belief by that form factor, and the price. I loaded it; a gig of ram, bluetooth, wifi, modem, big drive (for the day), the superdrive, and so forth. I bought every option because the more that was jammed into the box, the more I liked the form factor. I know it's a little weird, but there you have it.
Since then, I've used the little box daily, for just about everything. It's been powered up since I bought it (thanks to a UPS.) This year, a couple of months ago, I bought a Mac laptop - a top of the line 17" Mac Pro - but I still use the mini every day. I've rebooted the mini many times, almost always in response to an Apple upgrade or security modification, once when I went from 10.3 to 10.4, never as an attempt to fix a problem. I've never had any problems of that kind, frankly.
Today, without any particular warning, my Mac dimmed the screen, locked my mouse and keyboard, popped a black rectangle up which informed me in no uncertain terms that I needed to reboot. Now. I lost a long post I had been writing for Kuro5hin.org, and I failed to even reach the level of being annoyed about that because it was just so astonishing to me that the mini had actually - gulp - crashed.
I just want to say that I hadn't even realized that my expectations had been silently and sneakily leveraged to be so astonishingly high. After years of being screwed with, and over, by Microsoft operating systems, I no longer expect that an OS should, or will, crash. Massive kudos to Apple.