Hello there,
Not sure if this is a fact I do not know about but I came here to confirm.
I have recently purchased the new G3100 router as my main router with gigabit internet. I used to have a wcb6200q running over coax from when I had the g1100 going to the basement of the house. Since the wcb6200q is not compatible with the g3100 over coax (or not without a headache at least), I decided to try connecting it via ethernet instead. I purchased the wcb6200q from verizon directly.
From the g3100, I have an ethernet cable (lets call e1) running down to my basement, hits a generic tp link switch, then another ethernet cable (e2) into port 1 of the wcb6200q. When I plug my computer into port 2 on the wcb6200q, it is giving me ~500mbp speeds. I may be a complete novice here, but shouldn't this be near 1gbp? When I switch e2 back into my computer, I am getting near the 1gbp speed. Not sure if there is some limitation to the wcb6200q when feeding it with an ethernet connection. I thought it was capable of 1gbp speeds. The cables are also cat5e.
*edit: forgot to mention that I rented the g1100 router and need to return it with the purchase of the g3100.