Scott here, Richard.
http://www.srh.noaa.gov/data/obhistory/KSPG.html (which you mentioned)
is by far the best wind sensor in our area for Easts and NEs, imo.
I also use this sensor's readings for the skyway, and then add about 20% (because it's usually 20% windier at SW than Lassing). I have found that this sensor's readings correspond exceptionally well to the actual wind speed at Lassing over the years.
The reason the SW sensor reads REALLY high compared to Albert Whitted at times is because it is way out in the channel where the wind is stronger. The readings out there in the channel usually correspond pretty well to what the wind is doing at the Skyway and EB for SE, SSW, and S but don't correspond so well on NE winds (reads much higher in the channel than where we ride at the Skyway (or EB or Lassing).
It can read 20 in the channel, especially at around noon time on a NE and be as little as 11 more near land.
The only drawback to the AW sensor is that it only reads once an hour, not every few minutes. Despite that drawback, an accurate reading once on hour is more valuable than 20 bad ones an hour.