I'm a business user and am sold on the Treo 650. I'm trying to decide on a carrier.

I currently use Sprint with mixed results. I can live with it as it has gotten a lot better over the last year, but still calls are dropped fairly frequently. We have a corporate shared plan so it is very low cost.

I need: phone, e-mail, occassional internet access, and GPS navigation.

I've done a bunch of reading, but havn't gotten any clear answers to these questions:

1. Are there significant performance/reliability differences between the two services?

2. Does one service have a better implementation of features for the 650?

3. Are the costs different than standard mobile phones, and which service is a better value?

Thanks!