Blast! 120, only seeing ~80 Mbps, using an SB6121

I've just checked with Comcast and was told to expect 100 + Mbps speed from my service.  However I see only ~80.

I have Motorola  SB6121 and not sure what to make out of it.

Anybpdy esle have simialr issues and found soilutions?

Thx