Xe2 pods, routers, and modems

I switched to Xfinity a few months ago because my previous internet service was so unreliable. They installed an Arris modem (model SB6183) to which I connected my existing router. Again, widely varying wifi speeds (1-4 bars, mostly 1-2). Interestingly, my next-door neighbor's wifi is always much stronger, even through double walls. So I took out the Xfinity modem and bought the same modem/router that he uses (Motorola MG7700) and am *still* having difficulties. I had an Xfinity tech come by to move my access point into the house closer to the end of the house with the TV and my computer thinking that would help, but he suggested that I buy 1 or 2 of the Xe2 pods instead. 

My question for the folks here is: will the pods work with my new modem/router, or do I have to use the Xfinity modem? 

Thanks!