We're talking about two different things here. You're talking about the end user's connection. Net Neutrality is about the content providers' connection.
I have no problem with tiered bandwidth plans. I play online games and stream movies and TV shows over Hulu and Netflix so I gladly pay for the top tier service to have the most available bandwidth. My parents check email and read the news online so they have the basic tier. There's no need for everyone to have a 30/10 Internet connection.
To quote SaveTheInternet.com
"Net Neutrality means no discrimination. Net Neutrality prevents Internet providers from blocking, speeding up or slowing down Web content based on its source, ownership or destination....The free and open Internet brings with it the revolutionary possibility that any Internet site could have the reach of a TV or radio station. The loss of Net Neutrality would end this unparalleled opportunity for freedom of expression."
Since you cite Comcast as the example, they just bought NBC. Without Network Neutrality, what's to stop Comcast from throttling the ABC and CBS websites unless they pay for top tier service? The lack of neutrality undermines competition and traps us in a system where a few powerful corporations control the content we see and hear. When was the last time you heard independent music on a radio station that wasn't in a college town? ClearChannel decides what music you want to hear and then puts it on repeat.
The success of the Internet itself and the countless success stories that have arisen from the Internet are because of the unfettered access it gives you to the rest of the world. Anyone can create something and share it with everyone without a corporation deciding to charge them or even prevent them from sharing because it doesn't agree with the corporation's viewpoint.