Wonderful
Speedtest now shows my 75/35 tier as running at 84/32 was running about 60/20 before I switched it over to ethernet - that's also from a machines that is running triple nat'd on the in-house internal network.
I didn't rease the dhcp addr or anything, just ran the ethernet cable from the ont to the router and connected both ends and then called them and had them switch it. Took about 10 minutes including having to reboot the router after it switched from coax to ethernet - not totally sure why but it showed internet connection at the router and I could connect to the router from an in-house machine but couldn't get to the internet. After rebooting the router all works fine.