I'm about to go into a possible trial at work to give our sales team access to email on the move.
We're looking at 3 possible products (none of which are probably the latest versions due to acres of red tape to get the 'authorised' for use

)
So - has anyone used any of them, or similar, and might put one head and shoulders above the other 2?
My gut feel is that as phones, they will all be pants - just too big - so I'm really asking about the main use they will get - picking up and sending emails which may or may not have work style attachments (word docs, excel sheets possibly powerpoint)
Thank you!
models being considered are:
HP iPaq HW6915 - a PDA with phone bits bolted on
HTC TyTn (not TyTn II) - a phone with PDA bits bolted on
HTC X7500 - a mini laptop with no pretentions of being a phone at all
