I thought the Young debate had long gone away by now, but I'll bite....
Say we did take Young. We'd have Young and let's say the #19 pick in this year's draft like th Titans do.
Instead, we took Mario and we have the #10 pick. You COULD argue that a desperate team would be willing to trade a 2007 and 2008 2nd round picks to move from 19 to 10. Denver seems to be willing to move from 21 to 10 for a 2nd and a 3rd this year.
So, you could easily argue that the Young comparison becomes, which would you rather have:
Vince Young VS. Mario Williams AND Matt Schaub.
Schaub won't ever be the electrifying playmaker that Vince is, but he could end up being a much better pocket QB and to boot, we have Mario Williams. We won't ever know the grade of the '06 draft until we know how both Mario and Matt turn out.