Yes Jon, you state that evidence is on a continuum, I agree with your statement. However, since ultrasound has been around for a while why is there not better human evidence? If it is beneficial as you seem to believe why are there not better, more convincing human studies?
Thus far I don't really support U/S. Yes there is evidence in animal studies that it can work but so far in humans I haven't seen any supporting evidence. To me animals and humans are not the same. Personally I need more supporting human evidence. Also, it is practical to use U/S on a patient for 20 minutes in a clinic? I think not.