What you wrote vs. what I read...
I have their CORVETTE thingy whatever that means, but haven't noticed any faster speeds. I don't need THAT NASCAR PACE CAR SPEED so I CAN IMPRESS OTHER GEARHEADS SITTING AT A STOPLIGHT OR ANYTHING. I just DRIVE TO work, GO TO THE STORE, and DRIVE AROUND TOWN. The CORVETTE AND MY OLD CHEVY both seem to work the same in that aspect.
I am writing this at my inlaws who are getting 4 mbps. 146 slower than what you are getting...is that a gmg post maybe?