Great stuff
Firstly, it's a crime that Logitech couldn't be arsed to add OSX support for the $99 they charge for what is a dream of a mouse and so we have to pay another $15 to get the mouse to be fully functional via software that was essentially designed for another purpose. It's also annoying to know that this software ability is already within OSX (Expose) but its potential hasn't being fully realised. Too late for 10.3.3?
Secondly, the on/off switch would be convenient but I find I can get a whole 5 working days out of one charge. This is just using it in the office and rarely at home. I think one overnight charge every two days would be sufficient for a couple of hard days clicking. Swapping the batteries in and out will knacker the plastic door sooner rather than later I suspect. The other option is to take a look at mouser.com, find a nice little $2 microswitch and do it yourself. Lots of space around the batteries, drill a hole, snip a wire, solder and you're sorted. It's only a $99 mouse so never mind the warranty nonsense (as if they were ever going to honour it anyway).
Cheers,
Nick