616
I bought an s56 from the cingular store and I was back to return it before closing that day. The interface is a nightmare, and the screen is pretty lame, and all in all, it feels pretty flimsy. I bought the 616, as it was the only other BT phone offered. It cost $50 more, and looking back, I'd have paid 200 for it. It's an unbelievable device. It's where the s56 might be in another 2 years. The screen on it is so much better than that of the s56. The screen wasn't an issue when I was shopping initially, I expected that in the range I was looking, that I'd get something acceptable, but the s56 was like pulling a 14" crt of the box- I'd expected something more of an lcd, and then when I got the 616, I got the cinema display. Don't knock the camera on the 616 either, you never know when the moment will arise. It's fun from time to time, but not something overly useful.
The 616 interface is far better; my mother can save a phone number now, something she never was able to follow before. Any ringtones or images you send via BT go where they should, with the s56 you had to wade through a messy file structure and confirm a million times before you could save something.
At this point the 616 has become much more than a phone, it's my pda, alarm clock, remote control, and I would seriously consider taking it for a test run to check the signals in your area. I would also check to see that it's the phone model and not a CDMA(?)/GSM network thing. Up here in NE, they had just about gotten the network complete when they changed the equipment. Things were a little rocky during the summer, but no complaints any longer.
Also, if you purchase as a new customer from Best Buy, you can get a great deal, and a better return policy. The protection plan for $40 got me through 7 or 8 phones in the past 3 years, without upgrade fees.
Hope this helps, best of luck
td