Whoah. I think my brain blew a socket from reading that long post wink Might be easier to condense that for us folks who are easily distracted on the interwebs 8-).

To summarize Comcast's DOSCIS3 service, it's a great improvement. You can run simultaneous things such as online gaming and multiple downloads (on several PCs), without the typical slowdowns of DOCSIS2 service.

Don't get too bogged down in the details. You can easily buy your own modem, such as the SB6120, 6121 or 6141 and enjoy their upgraded service. You only see D3 modems on their list because they are moving all service areas to D3 service. FWIW, I have always had more issues dealing with the comcast issued Arris equipment than I have had with the vast majority of their Moto stuff. The last three Motorola modems I have not rented but owned too, with never any sort of rogue fee for phantom features that are no longer applicable. If you see such a fee on your bill, it means they did not provision your account properly, and you need to call CS.

The Blast tier is where you should start seeing immediate benefits of having a DOCSIS3 modem. It's possible though, if you are a heavy downloader, the 6120 on the Performance tier will still get you a bit of a bump in speed, due to less congestion/channel bonding. OTOH, Comcast is known for regularly bumping up speeds on various tiers w/o raising price. In this sense, if they bump up the performance tier to 16, then you likely see better performance than you would otherwise only having a DOCSIS2 modem. I'm not a heavy gamer, so increased upload speeds don't mean much to me, only how many simultaneous downloads I can maintain.

By all means go with your own wireless router vs their combo devices.