Put C7000 in bridge mode or buy a CM1000?

Hello,

I have Comcast and have the Nighthawk C7000. It has worked great! I wanted to see what I am missiong out on as far as a great router. I wanted to buy either XR500 gaming router...or the R8000 or R9000 (not sure which one yet...my biggest concern is some gaming since we like to play some Call of Duty and games like that so I'm thinking the XR500. My question is should I put my C7000 in bridge mode and use it in combination with the new router or should I just buy the CM1000 and sell the C7000? One benefit I see is that the CM1000 supports DOCSIS 3.1 and it is also 32x8 instead of the 24x8. Is there big difference in performance as far as 23x8 vs 32x8? Would buying a CM1000 be much better performance wise than just bridging the C7000 and any idea why?

Thanks!