DOCSIS 3.0 vs. what I have now?

no, but you should see the speeds you are paying for. 

You will be better served by making the switch. That model Toshiba has been grandfathered by Cox and is no longer supported. With Essentials you should be getting up to 3 Mbps downstream and 384 Kbps upstream.

The support article Cox Compatible Cable Modems shows you all current Cox supported cable modems.

I have switched to the Cisco modem and speed test confirm I am now getting what I pay for! But, multiple times a day the connection times out and I get an error message. Then a couple minutes later the modem reboots itself and the connection is back. Is this a bad modem?

A few questions first:

Are you a modem to PC connection with no home networking?

When you get the error where do you see it and what does it say?

Have to check your connections to make sure all of them are tight?

Is the coax coming from the wall directly to the cable modem or to a splitter first?

No router, straight USB from modem to computer. All connections are tight. Coaxial cable straight from wall to modem, no splitter. I get the "connection has timed-out" and "DNS unavailable" errors on the browser while browsing. Then the modem will reboot itself a few minutes later and will be good to go for about 15 minutes, then the error message pops-up and it starts over again.

Tech came out and got the firmware updated and that fixed the problem. Finally, getting the speed I've been paying for. Issue officially resolved! 

When I switched to a new Motorola SB6121 DOCSIS 3.0 modem, my speeds almost DOUBLED... more than what I'm paying for.  Make the switch to the Cisco.

Unfortunately, I haven't noticed an upgrade in speed after I was advised by Cox to purchase a DOCSIS 3.0 modem.. I have only notice a drop in speed... Good Luck...

The reason you havent seen an upgrade in speed, is cause Essential doesnt give you powerboost. Go up to Preferred, and youll easily get 15+ with that modem.

Doesn't preferred give you up to 18 and speedboost? I am nowhere near that speed. ***, my upload speeds are better than my download speeds... Not to mention the disconnects are picking up... 7 in the last 4 hours...