I am afraid I disagree with you, and agree with fimchick....
Havign said that I am almost certain I would point you in the direction of the ways to speed this up. Having said that I would advice caution in the registry hacking you will need to make to improve this.
Basically there are a couple of timeout to kill paramters - one is for Apps and one is for services I think.... you can change the apps one and it will just override any outstanding saving activity, so you might lose work in progress if you left things untidy at shutdown. Overriding the services killing timeout is more of a risky proposition, but with your RAID raptors you could probably half both and then see if you can trim more, or if you need to.
I have not tried looking back or browsing my registry to fidn these values - I am expecting you to maybe have some idea whereof I speak or to "STF W" as they say on IRC
Lemme know... chances are this will largely be the area you need to look in or you'll have something to say about it.... And I still think you are being finnickity to want a faster shutdown.... (IMHO shutdown should be a pretty rare event, maybe once or twice a month, so if it takes a bit what is the issue?)