It's like surveys - there are a lot of ways for Verizon to make that come out the way it did and you still get 500kbps downloads when you're sitting there.
Gigabit Ethernet from the Verizon tower to the speed test server is one way. If you're downloading from the testing server you'll get blazing speeds, but if you're downloading from halfway around the world, the download still won't finish by the time your plane boards.
And is that burst speed or thruput speed? I get all my downloads at home at 20mbps burst speed, even if it takes an hour to download a 1MB file. "Median" basically means "we did a few downloads and averaged them". It tells us nothing about what they actually did. I'm not overwhelmed. I'm not whelmed. I'm not even underwhelmed. (I wonder who paid for the survey.)
I get 3 times the "median" AT&T speed they show at the airports I've tried - and they're cheap regionals, not big-monied airports like Midway (IOW, I'm connecting to the same tower that everyone in town is). Figures don't lie, but they can be manipulated so far that their own mother wouldn't recognize them.