yo lab_rat_x they are top line stuff and they cost a lot of $$$$ here in Oz, Ive had a play with a cheap model for my cloning and man they really kicked, I was getting root fractals in 4 days, truly explosive.
I did have a few problems with the Ph when I used a nutrient solution for a flower I did, it keps oscillating wildly, I suspect the ultrasonic diffusion interfered with the chelates or the ferrous materials within solution...Im not 100% sure though.
interesting stuff at any rate and very 'tech'
regds
OzGrowa