As Furry said, unless you are technical enough to either trouble shoot or go back to the old firmware, then don't mess with what works.
I have already identified myself to TWC as someone intrested in doing IPV 6 testing and was questioned about my hardware, which was supposedly noted. Heck, they were shocked I already had a Docsis 3/IPV6 ready modem because they are barley rolling out Docsis 3 in my hood and a tech has to come to your house and and install a Docsis 3 modem, why, I have no clue. They remotely tested me and certified me for their fastest speed with no tech visit(40 bucks for the tech visit, NOT).
As I remember it, 2.02 was fairly stable except for IPV6, and it was a BEAR when I went to 2.05. It took me quite some time to get 2.05 working properly when I came from 2.02

The 2.06 upgrade for me was smooth, it did not even wipe my settings. But IPV6 is still way off for most, so this is something most can wait on if they are not having problems.
My kids and I will beat the heck out of it this weekend and see if there are any major bugs........