I ran the Syllable livecd in qemu (no acceleration). It's a bit sluggish (maybe because I'm running it without acceleration in qemu on a pentium M throttled to 600 MHz ) and it crashed once, but it certainly seems like a nice OS. It uses it's own GUI instead of X, so it's not a terribly useful system because of lack of apps, but that can change in the future, if someone ports gtk and the like to Syllable. If you just want to email, chat with jabber, surf the web, listen to music, etc etc, then it already is a good OS for you.
Double click timing is awkward, and the "terminal" desktop icon doesn't do anything, but I dare to guess these are liveCD/qemu only issues, and you won't get these problems if you install it.
CORRECTION!: The terminal actually does work if you log in as guest (password guest) instead of root (password root)
CORRECTION2!: Now it does work for root too. Weeeeeird.