Though I have a Teensy 3.1 I think this is probably the only real thing I had ever done using it so am not familiar with it enough to do detailed tests (I find the documentation on extra commands/features hard to find for Teensy, it could do with a proper reference page like for Arduino - but better) . The initial test program from #0 worked on all but the ST chip so the speed comparisons are what you would expect under normal programming.
If you can write a benchmark for the Teensy that uses standard system commands/libraries (or even hitting the hardware direct) then that would be a great addition to this post and probably the Teensy forum as well.