The Droid phones are really amazing in terms of functionality, though the biggest surprise for me is comparing the usability of the Droid vs the HTC Hero.
I've never liked virtual keyboards, so the Droid handily wins out here for me. However, the virtual desktop feels clunky on the Droid, but surprisingly useful on the Hero. In part, this is because the Hero comes with gorgeous widgets already set on the virtual desktop, providing easy access to photos, calendar, messages, and so on. These widgets are also far more useful than others I've looked for in the Android marketplace.
(I poked around to see if I could transfer the HTC widgets over to the Droid, but alas! It looks like these widgets requires additional software in the background. I'm hoping HTC will sell their widgets on the Android marketplace, but I doubt it since their goal is probably to differentiate their product so as to sell more hardware).
At any rate, if anyone knows of a good calendar app for Android, please let me know. It's embarrassing that my old trusty Palm Treo's calendar, which is not too different from the original Palm Calendar app, is far more useful and usable than a calendar app designed 15 years later.