Widgets are great. However we have noticed a few issues. Firstly, no aspx support! Second, if u declare a web part zone one that has widgets you can't change your mind without losing your widgets or. Manually setting them up again in another zone. Thirdly, widgets appear to lack the full configuration options even in design view that web parts have.
It would be good if you could just have web parts and configure their display on edit and live site without having to make them 'widgets'. Our developers find the concept a little confusing. Finally, we would like to have widgets but not allow user to drag and drop etc, but we seem to have to write custom css to remove this on the live site