I've been using it on my Incredible since yesterday and so far, it is pretty good. There are a few issues with it, hopefully they will get resolved soon. I consider this to be beta software, since the version number hasn't hit 1.0 yet.
For the weather and time to work properly, if your city isn't in the list, you need to specify your zip code (US only) as the region code, AND set the offset from GMT to get everything to display correctly. For the East Coast, the current offset is -5:00. Pressing on the + will change it to a -.
I'm currently using Calendar Pad to get around the Regina Calendar not syncing as I'm using a HTC Sense based phone. Haven't yet looked for a ToDo replacement. It would be nice if both of these Regina widgets would work properly on Sense based phones.
It would be nice if the home button worked like it does in Sense. When you are on a screen that isn't the main home screen, pressing home takes you there. If you are already there, then it zooms out and shows you thumbnails of all your screens. In Regina, pressing home zooms out, no matter what screen you are on.