Matt, I agree that adding too many filters can kill an image, but keep in mind, that was a joke coaster, so I didn't really car. I just thought it looked cool. If you like unedited pics, try the one I made for The Mikado.
http://www.weeweeslap.com/track_exchange/detail.asp?tid=13099
That has very few effects, and lets the coaster speak for itself.
I think that adding effects enhances the screenshot, especially if you are trying to enhance the theming of a ride. For example, if a coaster is supposed to be super fast, a blur might be called for to enhance the sense of speed. Likewise, if a coaster has no theming, but the author wants to leave an impression of theming without actually doing it, a filtered screenshot would be perfect.