Comcast tech told me I should replace my working docsis 2.0 modem with 3.0 because they were "phasing out 2.0".
However, when I called back, I was told that docsis 3.0 is only needed if I want more than 25 meg down.
Since I don't want to spend an extra $10/month to go from 25 meg to 50 meg, it sounds unnecessary.
Sadly, after I spoke to them the first time, I ordered a $70 docsis 3.0 modem which arrived yesterday. I'm trying to decide whether or not to return it or keep it.
I did read something that docsis 2.0 won't support ipv6 but I'm not sure how ipv6 would benefit me. I thought that was mainly to address running out of ipv4 addresses. I suspect comcast is nat-ing me an address so it won't affect me.