I have been running my primary development machine on XP Service Pack 2 Beta 2 with no detectable problems whatsoever for about 2 weeks. I have also installed it on several test machines of various types and a Virtual PC instance with no issues. I wanted to make sure the project I am lead on had no issues with SP 2. The only things I have found were what I expected, firewall warnings, dynamic content warnings, and a few minor bugs that I could have left alone.

I am fairly careful about downloads, so I probably do not have the spyware program 'winserv' state earlier, so I cannot speak of a problem with it. It does not show up with my spyware detection program or in my task list of running processes.

The explanation I have heard for the delay is that they wanted to make sure ISV's had a chance to test against it so there would be no issues. This could be an excuse, but my own experience has been positive. I think the 3 out of 5 number is anti-Microsoft FUD, the kind usually spread by Linux fanatics.

Since it is still in beta, I cannot recommend it for average users. However, any technically above-competent Windows user should feel comfortable in trying it (after an appropriate back-up that should be done with all OS upgrades).