Is it going to cost you more to rent, or do you own your current modem?
If you are renting, IMO, the upgraded technology is good thing.
HOWEVER, keep in mind that COMCAST is now enabling wireless access to other XFINITY users using a secondary wireless access to users near your home, served from your modem. It is segregated from your current home network, with a different, generic SSID - “xfinity-wifi” - I believe. They claim that it doesn’t decrease your bandwidth, but -— c’mon now, who are they kidding? They also claim that anybody using this second access point and doing illegal things, will not be traceable to your home network.
You can disable this functionality, but it is ENABLED by default. (and most people are unaware of it...)
Trust no-one. Especially COMCAST.
As if I need another reason to use my own router instead of one provided by the ISP.
bump
I own this current modem and if I upgrade to 3.0 I will buy one