Scott,
First thing you might try would be to run Amazing Utilities on the server, go to Advanced Options and then click on Test Speed To/From databases. Mine was under a second. Then run them from all of your clients. Again, all of mine were under a second. This may help you isolate where the problem is.
I would try to make sure all of your NICs are on autonegotiate. What switch are you using? Have you tried starting from square one and disconnect all buy one PC and see what the speed is?
I guess compared with ten minutes one minute is acceptable, but I would say anything over 10 seconds is not acceptable. Everything should be as fast as if you were on the server.
I have another idea, but I need to research it some.
