I have the 200 mbps service. I am using a 1 GBPS modem and router (Netgear Nighthawk AC2300 router and Nighthawk CM700 Cable modem).
I am averaging 20-30 MBPS. I have tried all the usual tricks, reboot everything, disconnect the spliter and connet the modem directly to main line, updated the firm ware, still no joy. I just decided to upgrade to the 1G service but if I'm going to have the same results, why bother?
For a test, what do you get with a computer connected directly to the CM700 modem (no router in the mix) ?