Where I work we build proof of concept demos(usually quite small) and then blow them up into full fledged applications(sometimes hundreds of pages).
We use Tapestry from day 1. You write less code when using Tapestry so it's easier to get demo up ang going. Then we take the demo pages and build on it until all of a sudden there are hundreds of pages. There is no "throwaway" Tapestry code.
So, IMHO Tapestry is an excellent choice for any project.
Disclaimer: I'm a Tapestry committer and the Spindle Guy. [ May 28, 2004: Message edited by: Geoff Longman ]