Rated 1 out of 5 stars

I recently upgraded to the latest version to find the user interface has changed with the drop downs missing. There is no way to revert this change except to uninstall the upgraded version and downgrade to a previous working version.

DO NOT UPGRADE!

Edit: Everything below added after the developer reply.

Thank you for returning the mouse drop down lists in version 4.0.6! I have not tested it yet, but I hope I can just disable the text input entirely. The rating/review above is for version 4.0.4 *without* the mouse drop down lists and I stand by the one star review because there was a significant interface change without an option to disable it.

For anyone else that just doesn't want to use any new interfaces or tweak any options, you can install the last known good version 3.3.10 from here:

https://addons.mozilla.org/en-us/thunderbird/addon/send-later-3/versions/?page=1#version-3.3.10

You can also stop all automatic updates for addons by editing the update options:

http://blogmines.com/blog/2010/12/27/how-to-disable-automatic-check-for-updates-in-mozilla-thunderbird/

You can also edit the about:config options in Thunderbird to change extensions.update.autoUpdateDefault from true to false.

This review is for a previous version of the add-on (4.0.4). 

... how fast users can turn on you when you do something that irks them.

I'm sorry you don't like the free-form date/time input interface, but I hardly think that warrants a one-star review, which I, at least, reserve for software that is completely unuseable. Really? You find the add-on completely useless with the new interface? I find that surprising.

Having said that, mouse-based input is back as an option in version 4.0.6. You can upgrade manually now at https://addons.mozilla.org/en-US/thunderbird/addon/send-later-3/versions/4.0.6 or wait a week or so until the new version is approved by the editors and you are upgraded automatically.