Hi!
I see that this RPM reading has caused some "surprise". Just for the sake of good order, the reading of 10100 RPM was made on a JXF 14x6. On APC 14x6, the ASP 52 made 10000 RPM. RPM-readings were confirmed by two different tachs. Measured to 4,5 kg (10 lbf) thrust.
Here is a video of a RPM-test with the APC 14x6.
http://www.youtube.com/watch?v=KMmrnIJNcZI