Cheers for the confirmation. I bit the bullet in the end and went for it, and can also confirm to anyone else reading this that TomTom6 works wonderfully on the Treo 750v. The traffic and speed camera updates are well worth subscribing to as well.
For anyone reading this struggling to get their 750v to connect with a bluetooth GPS unit under Windows Mobile,
this guide from Microsoft's blog came in very handy for me. Combine it with
this article on TomTom's support page from step 18 onwards and you should be good to go.