I spend much of my time using Windows (2K pro, 2003, XP, and Vista) and OS X , and a little on Linux. I consider myself experienced with both OS X and Windows. I much prefer OS X but I can say there is also some things I like about Vista. I have not had any speed issues and only a few software compatibility issues. I appreciate the structural improvements made in such areas as the management console, event logger, command line utilities, and kernel structures. Vista isn't the upgrade it should have been but it is not horrible. Microsoft is on the right track with UAC, and with some fine tuning it will be worth the trouble. The display subsystem is moving in the same direction that NeXT aka OS X took 15 or so years ago (think display post script in NeXT, now display PDF in OS X). It's taken Microsoft far too long to catch up but I do think they are on the right track. Remember the resistance XP met with when it first arrived. Now it's well received. I think Vista will eventually achieve this status a few years down the road.