Thanks for all the advice and information. Very useful.
Went to WCC tonight and I settled for the Treo 680 in the end. The main reason being is that it seems to stack up well against the competition, is reasonably priced compared to others ($3700) and, probably the main reason, I can connect it to my laptop and sync with Lotus Notes, our work email system.
For some reason as yet not explained to me, we are not allowed to use ActiveSync so that rules Windows Mobile out.
Thanks again for all your help.