That close could be a problem It is actually a good thing you were not only 300 feet away from the equipment, as being that close can cause problems, unless a signal attenuator is installed, which more or less is equivalent to adding more distance between you and the VRAD.
That said, you are most likely close enough to have unusually high signal quality, and so could potentially qualify for even higher speed in the future if AT&T decides to offer them.
Yes, your install was atypical. Then again, so was mine. They say 4 hours is typical, but my installer was here for a whopping 45 minutes, since my setup was dead simple, all my cabling was good, and my installer was well practiced, performing at an incredible speed while not sacrificing quality.