The Bitter Script Reader at 2010-01-31 17:31:18:
What's my first impression when I see that my next read is only 80 pages? "Yippie! This'll be fast!"
Though I admit, my first thought after that is that it would probably be a lot easier to justify giving a consider to a script with a little more length - the impression being that a script that short would lack depth. However, I think Scott is already giving the best advice one can give in that situation - see if there's more that you can add to the story - not just for the sake of adding length, but adding depth.
On the other hand - I recall reading the script for FEAST soon after it won Project Greenlight, and it too was little more than 80 pages. Not only did both I and the Development VP who got the script have a bit of a laugh about the length, we also felt that as a piece of writing, it was utter garbage.
But the movie apparently did well enough on its budget to merit two further sequels, and the entire production process made for a hell of an entertaining third season of PROJECT GREENLIGHT, so what do I know?