All speed tests are only a teaser unless you can also tell us your signal strength at the time of the test. Settings | About phone | Network (some settings menus may differ). I've has as good as 17 ASU here in Santa Clara, but I didn't have a chance to test.
And moreover which type of network and what that ASU is based off of (arbitrary signal units)? Even the signal in decibel miliwatts is potentially measuring one of several things, and it gets complicated when there are multiple transmission and reception antenna.
You can have a strong signal with high noise and without indicating signal to noise ratio just the signal strength won't tell you what the radio conditions are.
I suppose the value that should be reported is what the handset is reporting to the tower, which is how the tower determines what code rate and modulation to use.
And on the flip side, there is no way to determine what the tower is seeing for radio conditions, so the handset to tower (upload) portion of the speed test doesn't have a recpricol rssi or asu value you can report.