Getting back to the initial intent of this thread, you CAN use Pro Tools and VSL together successfully. Many of us do. Now moving on...
Speaking about Pro Tools TDM and not LE - as you're not going to invest those kind of dollars in TDM hardware if audio isn't at the top of your list of priorities....
Pro Tools is first and foremost an AUDIO recorder, editor and mixing solution. Most of the major recording studios and audio post houses that I have worked in use Pro Tools, not Cubase or Logic or DP. I use Pro Tools, Digital Performer and Logic and Pro Tools is in my OPINION the hands down winner for audio work. As I've said elsewhere on the forum, Midi in Pro Tools is like early Vision (and not even). But it works just fine.
@Another User said:
Then again, that doesn't take into account a friend's friend who recently lost a Mick Jagger vocal take when it decided to have a bad day. [:)] (True story.)
To be fair, I have seen almost every major brand of hardware and software fail at one point or another, and at the worst moment, regardless of who is in the room. If that was a qualifier there wouldn't be anyone left in the industry to buy from.
Bill