I paid to run the Public Beta in 2000 on my then-top-of-the-line dual 0.5 GHz G4 Power Mac. I ran it (and the subsequent numerous leaked dev seeds) as my day-to-day OS and only rebooted back to OS 9 for the occasional CD burning or DVD-watching (which didn't work until 10.1).
The early versions were slow as hell, but boy were they brimming with potential!
It got faster when they removed the debug code, though.
