I have a MBP running Lion and an iMac (I'm not the admin) running SL. I'm finding it really hard switching between the two... The obvious thing is the scrolling. In SL, I keep having small panics where I think 'Oh no, the mouse isn't working?!', and then realise I'm scrolling the wrong way Other things have proved to be more useful than I thought - I keep doing the three finger up gesture to show Mission Control, but of course it's not there! The last thing I found was that SL looked so... dated. All the aqua and rounded buttons looked like they came out of, err, 2009! So, could you go back?