I've used the app since its release .. impressed indeed! Helps to make those crappy earbuds sound quite a bit better. I use Amarra Symphony w/iRC, which is an integrated Amarra/Dirac module, on my Mac mini. It was game-changing for me. It's a bit on the expensive side but was well worth it for me .. YMMV of course. Lot's of info on computeraudiophile.com about Symphony w/iRC and the stand-alone Dirac software.