down/up is more funner for the themer :D

There is a trend of our gracious coders adding better mouse events support to modules (among them include wheel and drag n' drop), and this just another thing we want.

The obvious need for button-down is that you could have actions that execute on button down instead of on the release as most clicks do it. This would practically save you milliseconds of time as long as you clicked the intended target. =D

Less anal but more clumsy, I'd like to try some of that simulated dragging that you can do with this down/up support; at least for now you can interactively move and resize modules' windows so long as they provide !move and !size bangs (most do). There should be more uses than just these.

Also with down/up, you can have 'hold' actions (hold the button for a duration).

As Smurth implies, consistency is good and much desired. A lack of standardised module behaviour limits our [themers'] plans.

The reality is not ideal as we'd like, so we're just hacking away alternative fixes in the meantime.