I have Cleartype enabled on both my Sony Vaio laptop LCD and my Dell Axim X30 - makes a good deal of difference on both. As you can see from the mixed response the combination of monitor, video card, and eyesight make a lot of difference from user to user.
Those who find Cleartype "fuzzy" might want to check your monitor/video card settings and see if raising the video refresh rate helps. If your monitor and card support it that will also make a diff. (Disclaimer - Do this at your own risk - don't touch things you don't know anything about unless you're pretty confident you can get yourself outta the mess you make!)