Now that the MacBook Pro has been released with just a single Firewire 800 port I'm curious as to how this compares with my 1.67GHz PowerBook G4 which has two Firewire ports (one Firewire 400 and one Firewire 800 port). I read somewhere that if you daisy chain a mix of Firewire 400 and 800 devices, the fastest device will drop its speed down to the slowest one in the chain (e.g. if I daisy-chain a Mini-DV camcorder (Firewire 400) to a Firewire 800 hard drive, the hard drive will only be able to work at 400 speeds). Is there any truth to this? And what about my Powerbook G4 with one physical port for each speed? Are there two actual Firewire busses inside, meaning they're totally separated from each other and thus will allow me to connect say the camcorder to the 400 port, the hard drive to the 800 port and thus have the hard drive work at 800 speeds? Finally, is there a (free/cheap) software tool which will help me check transfer speeds for these kind of things?