I think they are pretty good with keeping good cell phones on market, not as good as AT&T but pretty close. You can also look into purchasing unlocked GSM phones on eBay, so that would give you a wider range of phones to choose from.
I agree , I love T-Mobile they have great coverage in my area , they have fantastic customer service, but their phones have alot to be desired. I am looking for an unlocked wi- fi phone , seeing how my internet service has a hot spot add on. I am currently using an unlocked Palm Centro from AT & T I got off here..pics,video , everything worked right out of the box.