I just bought the 2012 iMac, reluctantly, because of lack of firewire. The guy at the store assured me that the adapters provide solution. My interface is firewire 400. There are no thunderbolt - 400 adaptors. So I had to daisy-chain 400 - 800, then 800 - thunderbolt. Salesman assured me no problems. Reality suggests otherwise. First try - half volume, lost frequencies, crackles and pops. Second try, fuller volume, questionable frequency range, ... but can I trust it at all for professional work? Any pro audio engineers our their that can attest to the reliability and professionalism of daisy-chained adaptor solution? Help!