My company is providing me with a Blackberry. Here are the choices:

8703e Sprint CDMA
7520 Nextel iDen
8700g T-Mobile GSM
7105t T-Mobile GSM
7100i Nextel iDen
7120e Sprint CDMA

Thumbs up/ Thumbs down?

I am in NJ. How does Sprint compare to Nextel compare to T-Mobile?

What is the difference between CDMA, iDen and GSM?

Thanks!