I'm not trying to pick a fight with you, either . . .
but I feel it neccesary to correct some of the inacuracies in your post . . .
Avid is gonna lose that monopoly position and maybe they are gonna start to make their products ( PT ) compatible with other stuff...People "have" to buy their interfaces to run PT.
NOBODY has to buy a Digidesign interface to use PT, but the other options are MORE EXPENSIVE than those Digidesign interfaces!
With the "professional" system, PT-HD, the software comes "bundeled" with 1,2 or 3 Accel PCI processor cards . . . you DO have to use AT LEAST one Accel PCI processor card for PT to work, but you CAN use another companies' interface(s).
And PT IS compatible with LOTS of products (CPUs, Plug-ins, hard-disks, etc) . . .
And, IIRC, none of the OTHER platforms are "compatble" with each other - you can't open a Cubase "session" (song) with Logic, for example . . .
...because the cpu are now so powerfull , we don't need those PCI processing cards ( axcel ) anymore.
Maybe YOU don't need the extra processing available through the use of Accel cards, but I DO!
And, as I've said, I use a relatively fast, dual-processor G-5 with lots of ram and 3 Accel cards (HD-3).
I DON'T use all of the available resources . . . but I am OFTEN using as much as 60-70% of the "extra" power that the 3 Accel cards provide . . .
as always, YMMV, IMO, IME, etc . . .