Hi. I have a Cingular cell phone account and my daugter uses T-Mobile.
The main difference seems to be coverage. We go camping and everytime we have gone (sites are not "in the middle of nowhere but in state parks), T-Mobile has no service.
Cingular always has had coverage everywhere I have gone. Never had a problem with clarity or range.
My daughter says T-Mobile offers free calls between her and her boyfriend, that's the only advantage to T- Mobile she believes.
On the Cingular negative side: their customer service stinks. They have "franchise stores" and "corporate stores" both call themselves "Cingular" stores but both give conflicting information to the customer and neither know what they are doing and will both tell you conflicting things. Add a "Best Buy" representative or their internet site and you're really confused!!
Cingular customer service isn't sympathetic when you are told the wrong thing by a franchise store, etc., it's your "tough luck".
Make sure when you sign your contract, it's in a corporate store.
Because of the poor customer service (the misinformation has cost me hundreds and hundreds of dollars) I am seriously considering not re-signing my contract. That is a shame because the connection is clear and overall a great product. They just can't get it together.
Good luck and hope this helps. Debbie
I'm currently in the market for a phone from either of the services. Because I need the most minutes I can get, I've picked the two providers. Now the decision will lie over the coverage in my area and the phones they provide. I want a genuine opinion of the experience using either service with a phone because I'm also hoping to get a phone that has a solid call quality. Hope someone can help.

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