Is there such a thing as too many custom meta tag entries

As the title asks, I was looking over my queries being called, and I noticed nodewords in most of them. That got me to thinking, is there a point where a site has made too many custom page meta tags?
If you have several token lookups on each custom meta tag, wouldn't that also slow it down?
I wish I could take the time to tear into nodeword's code to figure this out, but we're just so close to finally getting our site up, and I don't want to get too sidetracked. I'm just looking for ways to speed up our pages.