I got this phone about 4 years ago. At the time, it cost $99.99 on top of the rebate for signing up. It had pretty good features for the time, and even today, it stands out as pretty technically advanced.
I bought it mainly because it has bluetooth capabilities, which makes it easy to communicate with my computer. I can sync my contacts with my my contacts in Outlook for example. I even found a program online that allowed me to control various programs such as Windows Media Player, WinAmp, PowerPoint, etc. with my phone.
It can also access the internet, but as I didn't sign up for a data plan, it is very expensive and I don't really use it.
The reception is very nice. I often get reception in places that my friends (who are also using Cingular) don't.
It is very customizable, you can change the wallpaper, the fade out screen, etc. It doesn't have as much support for ringtones as current phones, but I don't really find that very useful.
My major complaint is the screen. It is not very bright, and in very bright sunlight, it often becomes very hard to see. Also, dust seems to somehow seep under it, and after 4 years of use, there are places on the screen where I can see little dust particles that are permanently lodged under the screen.
Overall, it is a very good phone. Although I will upgrade the next time my plan rolls over, I have been very satisfied with this T616.