LW,
The Sony PDAs are probably the best Palm based machines on the Market. I use two models with my Powerbook on OSX and love them.
Here is one catch. Sony and MacOS will not synch via Cable connection out of the box. To use the USB cables, you have to buy a third party product called "The Missing Synch". As I understand it, this was a Sony decision, not an Apple issue.
In my case, I use Infrared to synch. That will work out of the box without any third part apps. If you have an IR equipped machine, you need buy nothing else.
So, build 30.00 into your price decision when making your purchase. I think the SL10 is a wonderful machine.