Regarding pricing: HDTV is an extra $10/month. There is also a $7/mo charge for the modem/gateway. The installation charge is $99.
For one HD TV, no DVR, and 18 Mbps Internet, the monthly charge is $56. The one time charge is $99.
There are plenty of options to add additional channels, additional TVs, and faster Internet service. You can visit the ATT web site (as I did) to see the various possibilities.
Regarding reliability: I've had Uverse Internet for 4 years with almost zero problems. I cannot remember the last time I had a service outage. It has been more reliable than my power service. Can't speak directly to the TV service, but several friends who have the service are very satisfied.
Pricing: I've two choices: AT&T and TWC. AT&T is very price competitive with TWC and has much better customer service. It would be great to have Google Fiber or Vz Fios as an option to drive some competition, but that won't be happening in my area anytime soon.
The net result is that it looks like an OK, not great, deal. You get local TV service (if an antenna isn't an option for you) and a decent Internet speed for a bit of a discount. They toss in Amazon Prime to offset the installation cost.
I also checked TWC pricing. Their closest package (local TV w/ HD, 15 Mbps Internet, modem w/ wifi) is $70 per month for 12 months. There is no installation fee for self install. It costs $15 to have TWC visit your house & install.
This is for Dallas, TX. YMMV in other areas.