Arizona Gigablast - 350-400ish max

I've contacted tech support, I just had a tech over today who swapped somethings out on the wiring outside along with swapping out new modem. He kept getting between 250-400 even though his meter said 1100, he contacted someone else and they said that the site we're testing our speed on is just showing the wrong speed. I test the speed and still only see 300-400 speeds. 

Whats going on here? this isn't anything on my end.