Upgrading modem - what should I get?

First, do you have Cox phone service? If so, then you might be able to upgrade to a newer phone gateway for free. However I normally don't suggest gateways over having a separate modem and router like you have now.

Second, what kind of performance are you getting out of your current hardware? What are you trying to improve? For instance, if your speed direct to the modem is sometimes slow, upgrading the modem could help. However, if your problem is low wireless strength, then a new router would help. 

Recommendations:
SB6183

CM600

Stay away from SB6190 and CM700 for now, still several firmware revisions from being *good*, if the problems can be fixed via firmware....

No, I don't have the phone service - just TV and internet.  My connection service is fine but I think it could be better.  That's why I asked the service rep.  Since I'm not familiar with the modem/router combos - are there advantages or disadvantages to them?  

Thanks!

Modem and router combinations are something I avoid whenever I can, for several reasons:

• You are at the mercy of the ISP for firmware updates for the router.
• If the modem fails, or the router, instead of replacing that one device, you need to replace the whole unit.
• There are more limits as to what you can adjust in the settings for a gateway (not so much anymore, but there are still things closed off).
• Some gateways have a 'backdoor' such that the ISP can reset or get at your wifi settings.  Having that available worries me that some malicious people might figure out a way to exploit that.
• I don't have the option for custom firmware (DD-WRT, OpenWRT, Merlin/Asus, etc) for the router.
• A router can be used with any ISP (cable/fiber/etc) and the modem must chosen for the ISP's specific technology.

So I generally recommend separate devices instead of combo units.

Thank you, that is very helpful!  So perhaps I should stick with my current router and upgrade my modem to a SB 6183 which I can buy from Amazon and likely elsewhere.  

LinusC, I totally agree with everything grymwulf said about gateways, I never recommend them also.

About your router, it is wireless "n" and you will never get full Premier speeds over WiFi using "n".  The practical limit is about 75 to 80Mbps over "n".  If you have clients that support "ac", you may want to think about upgrading your router to an "ac" device.  If all your clients are "n", stick with what you have.

Thank you.  That's good to know about the router.  I will check but am due to upgrade my laptop shortly so it sounds like a new router might be helpful.  Any recommendations?

ASUS, like the RT-AC68U, makes a good router.  Also, Netgear Nighthawks like the R7000 are also good.  They are in the $150-200 range.  If your budget can't handle that, TP-Link Archer C7 comes in at about $100.

The Archer C5 from TP-Link (AC1200) is right around $60, so it's unbelievably affordable for its performance.  C7 (AC1750) is $86, and AC1900 C9 is around $150 - which is right around the other AC1900 routers: Asus RT-68W $140 (same as RT-68U but white and $10 cheaper) or the Netgear R7000 $180.