dude, I'm not saying that you will be able to record onto 16 individual tracks into pro tools, I'm saying that if you wanted to, you can use S/PDIF as an extender..that is y I said it DEPENDS on how you want to use your system..It's the same as if I take an analogue board with 48 inputs, run it into one channel of my mbox, and record. Will it be one track in PT, of course! but can I record more than one track at a time..sure..
And if you think this is a crazy way of working, that argument definitely has merits. But do some dudes do it, obviously.
It has obvious advantages for ppl who are sure of what they are recording and just want a stereo mix from many mono takes....like a drum set for instance..