I've been running the RTM since it came out on Technet too, and it really is worth the upgrade. I didn't like Vista at all, but W7 takes all the prettiness (and more), and runs on systems that Vista would have slowed to a crawl. Add in the fact that it installs quickly, recognises a staggering amount of hardware out of the box and hasn't crashed a single time since I installed it (Beta/RC1 included), and you can colour me impressed