Ultimate Internet speed

I know this will sound like a worn out record, but I upgraded to the Cox Ultimate Internet package from premier.  Before upgrading I speed tested my connection using the tool at the Cox website.  While on Premier, both wired and wireless,  I was consistently getting 90-120 download and 25-30 upload.  That what the Premier package offered. 

I upgraded to Ultimate.  Using the Cox speedtest service I'm still getting about 90-110 download and now about 35-40 upload.  The upload is in the ballpark of what Ultimate offers--the download is well short of the 150 (188 Powerboost) speeds.

Cox tech support reprovisioned the new modem, Motorola SB6141, a couple of times.  It is capable of speeds well in excess of 100.  I reset the new Airport Extreme router, changed channels for both the 2.4 and 5ghz spectrums.  Link speed is not an issue--5ghz over the router shows 135-150 depending on the room in which I am standing.  Don't know if this is a factor, however, the 5ghz transmit rate on the computer at which I am running the speed test fluctuates between 162 and 216.

Cox Customer Support confirmed Ultimate package is at 150 download and 50 upload in my neighborhood.  I'm at a loss as to the problems and fix(es).  Any pearls of wisdom of anything that can be done on the Cox end short of a technician coming out to check connections, the modem, which is new, etc?