Don't forget that on the consumer side, anything above 1Gb is an entirely different kettle of fish. We can achieve 1Gb over the most common cat5/e cables (1000BASE-T) but they simply don't support carrying anything more, same goes for the NIC on most computers, it's just not common to get anything above 1Gb.

The main benefit that is reasonably achievable for most people would be that they could aggregate at over a Gb, so they could connect multiple devices and expect a full Gb for each. Even then you would have to ensure they either both connect to the router directly or you have > 1Gb towards any switches (either 10Gb or LAG).

Achieving more than 1Gb on a single device would require the use of both cat6e cable or fiber and having a 10Gb NIC on that device - this is assuming the Comcast router even has 10Gb ports! And even then I'm sure they're would be some other hardware/firmware/software issues to tackle...

An interesting problem though....as for delivery, it could be using GPON, most active point to point is either 1 or 10Gb whereas most existing GPON ports support up to 2.5Gb which seems to fit better.