I just spoke with a Woodpecker's representative. He said that FinnForm
is not the best choice for router table tops because of flatness issues
(for the tolerances expected in cabinet/furniture making). He'd
recommend something thicker and flatter. He said if you use FinnForm,
you should have plenty of support fron underneath.

He suggested several options: layering the Finnform, using baltic
birch, using the commercial router tops like the one's from Woodpeckers
or other manufacturers, etc.

In general I thought he was quite honest and not just trying to make a
buck by selling to me. I felt he was concerned about my satisfaction as
a customer, which in the end helps him make a buck since I'm likely to
sing Woodpeckers' praises in places like rec.woodworking....