does the above mean that one of the versions is powermix in combination with audiomedia III? or is audiomedia III one of the 4 versions.. apart from powermix ..
It's the same (digidesign lists them on the same page in their pdf here:
http://archive.digidesign.com/support/compat/). Not sure about Digi 001 with it. But if I had a Digi 001, I'd go straight to 5.

ProTools 4 lacks a big feature: it doesn't have a master volume.
http://archive.digidesign.com/compato/The main interest for PT 4 imho is that you can have 16 voices without any required hardware. I used it a lot and still use it just because of that. I think I have the same installer (4.3.1) that mac garden has from way back when, and I should note that you have to allocate more memory to the DAE rightaway and I think you have to change its prefs for it to give you 16 voices. Out of a fresh install it gives you 4 or 8.
The installer also puts in a few TDM plug-ins in there, which are obviously of no use without hardware... which makes me wonder if it's not just the same application for all versions mentionned in your article.

(for example the TDM mixer gets installed which is needed only for ProTools III and/or ProTools | 24)
As for older version, I can make a bundle of 4.0.1.. It's very similar to 4.3.1 but 4.3.1. has an extra button which puts the hand, the cutter and the cursor in one button which, when selected, makes the mouse behave differently depending on which key you press (something like option means cutter, command means hand... ). Another difference is that when you cut 2 sounds together (let's say you're editing speech using shuffle mode) 4.3.1. will "correct" the last sample of the waveform to fit the next "new" sample. This looks like a detail but it's a major improvement especially when you're in a rush .
