Road runner is the sh1t! I have Embarq (formally known as Sprint) I have their 5.0mb ADSL account (49.95 A month) and I would much rather have road runner (cable) where I live they do not provide service in my area. So my options are very limited and the best option for me is embarq over the choices.
I live in major city in south florida, so go figure. My cuz has it (comcast) and the speed is much faster and he lives 10 miles from my house. when he came to my house and jumped on the net using notebook to download and surf the net he said get cable not adsl.
On a side note, All ISP's have specific EULA, (END USER LICENSE AGREEMENT) privacy policy, and Acceptable Use Policy, & TOS (Terms of Service) etc...
I usually go by those or whats provided in my area, and base my decision on that. I use my computers for different purposes than most home users.
Comcast is great if you love a company that throttles everything, has thousands of hidden charges for just about everything and has horrible customer support.