Time Warner offers a decent product for the cost. We have often relied on them when Internet service has been crucial, and 75% of the time, the service has been there when we needed it. At other times, though, the service has been impeded, or worse, not there at all.
Customer service is iffy, too, at Time Warner. At times they do a great job getting you connected to the people you need. At other times, customer service seems to know exactly where they have you (by the short ones!), and they treat you as such! For example, we live in an area where we are sort of shoehorned into who we're allowed for Internet/cable providers. Our city sort of divies us up, giving one part to one company, another part to another company, and so on and so forth. So, even if we _wanted_ to change, we couldn't. Why this is good for consumerism is beyond us, but it's not like we were ever consulted on it. =P
Like I said, though, Time Warner Customer Service knows all about this. So even threatening to take our business elsewhere is met with, "Mmm, I don't think that's an option, Mrs. Todd. I believe your area has a contact with..." and it's then that you know you're dead in the water.
Now, I can say that even if that's not a successful ploy, even if they take the wind out of your sails, they'll always come back with a way to help you. Whether that's in a form of a rebate, or saving you (a bundle) on a bundle, or new service, etc., whatever, they're usually pretty willing. It's usually just a matter of telling them what it'll take to make you happy. They don't seem to want to go out of their way to end a relationship badly, if you know what I mean.
Ultimately, I'd give Time Warner 3 of 5 stars. I liked Comcast better, but I'm not wholly chuffed that we have to work with TM. They're usually reliable, and where there's a beef, there's usually a solution.