Nice article. You inspired me to add a few counters (to my cluttered mess!)  that I was missing.

Three Points

1.I believe the "System Object : Avg. Disk Queue Length" actually belongs to physical disk.

2.While you mention it, the importance of looking at individual disks and processors and not just the totals can not be overstated. The devil is often in the details.

3.It also helps to look at the usage of the paging file.

Terry Duffy