I've had T-Mobile for a couple of years now. It's not too terrible. In most places I have decent coverage. T-mobile has the best plan for me $29.99 for $300 anytime, unlimited weekend, long distance and roaming included.

Every other plan I see that is comparable is $35+

 

I'm with Verizon currently - good coverage but they charge many $s for everything (for example $20 a month for Outlook sync!!).

I wanted to check out the T-Mobile plans and also the Sidekick 2. However, I was wary about network coverage, particularly because one of my co-workers has trouble with his.

Anyway, the guy in the Palo Alto store was very helpful, and pointed out that, if you are a new customer, you can buy a phone+plan and return it within 30 days if you are not satisfied - no questions asked, as long as you return all hardward+packaging in pristine condition. They will only charge you the month's service + overages if you get any.

This seemed like a good idea, so I went for it. The good stuff was that the phone works at home, at Squaw Valley, Alpine Meadows, Tahoe City - even in the boonies outside town. It also worked along I80 coming home. My GF was using it to play an on-line trivia game for almost all of the journey.

The only place I don't get coverage is at work in Palo Alto (Cal. Ave.) - even if I go outside. The irony is that I work right across the street from Danger Inc. who make the device.

I'm in a quandry now because I really like the phone, but it is annoying that it doesn't work in the middle of Palo Alto - Doh!

 

My T-Mobile doesn't work well in my office. It seems that the corner I am on is spotty. I pay $40 a month and it covers my needs. That is much less then the cost from competitors.

 

T-mobile meets most of my needs. Their coverage is not very good in some areas in California but 95% of the time when I use it, it is fine.

If you need good coverage, Verizon is very good here. Cingular will be better than T-mobile as well. It seems like T-mobile still has the best phone plans though.