Dan, when you did that test did you adjust the hammer spring for each pressure setting ?
Port size also play a big role in consistancy. From what I've seen the TM's generally come with smaller ports than the Theoben's used to......
Then the port must be the restrickter in this case, therefore the same Ave speed. That will also explain the very small ES, but the rifle might not be tuned for optimal air usage (shotcount) I think.