After a message in the extreme programming mailing list, I sent the execution times of PAFlow unit tests to Kent Beck.
He used google charts to plot the results, and here are the data :-)
Just to explain what is going on: the x are the execution times, and the y are the number of tests which have that execution times. Both scales are logarithmic, with the y which is 1 at start and 1000 at top. 4096 actually means 4096 millisec.