[ArcBody]

Not the answer to your question - but this info may help, a little.
I use Sprint PCS BC in a limited way and find it very effective for my needs.
No link to a "constant-on" system w/Outlook - in my case.
I have my Treo set to download ONLY "Headers".
Spam overload would be a real problem otherwise.
When I get an important, authentic email, I select to download it (text 1st).
This is usually satisfactory.
I don't expect my 3rd Generation Treo w/32 MB Ram, etc. to be a laptop.
Usually I have a couple of Laptops with me and unlimited internet service with Sprint PCS and Verizon via Sprint's AirPrime 3220 and Verizon's AirPrime 5200 Card Bus PCMCIA Cards. If the laptop card's signal is marginal, I use an "internal" or "Mag-Mount" External Antenna, connected to either card for 3 db gain reception.

This may not be a suitable answer to your question - but it is a very effective solution for mission critical applications.