Nima, if you have a spare server with an AOLserver instance (or where you can install it), here is another thing you could try first before diving deeper into system statistics gathering:
A fast way to find out whether your problem is solely your dynamic server box would be to set up a second AOLserver on a separate physical server to access your database and fire it up.
You don't have to worry about a cluster yet as you don't have to put it into production. Just browse your site using the second instance during peak times. Since you will have 150+ users on your production site, but only 1 user on the second system, you will see how fast the response times on your second server compared to the production server.
If the response times are much faster as you would usually expect them on your production site without too many users, then concentrate on the dynamic server first. If you still have longer response times than expected, you will have to keep gathering more information and statistics first as mentioned.
