ok gents, back all this up a notch...
1st off, there are several grades of EPS available to board builders - and the public/backyard guys. The cheap, low density stuff found in most popouts will most certainly absorb water like a sponge, especially in places like the uk where the air is usually warmer than the sea, and the foam drinks it all in as it effectively shrinks due to temperature changes.
There are several superfused EPS blanks available that do absorb some water when dinged, but no more than a poly build. Some are closed cells too, so they limit water ingress very well.
XTR/IXPS is good stuff, but it does delam if it gets hot, or gets crushed over time. Actually, it doesn't delaminate, it shears off of the foam due to the fact it is totally closed cell, and the resin doesn't penetrate it like other foams. I built loads of these in the UK, and as far as I know, they're still going, ahem, strong. Hard to shape, finicky to glass, but bomber strong if looked after.
FW and all their copycats are only a small section of the composite side of surfboards. The US has loads of guys(actual surfer labor...) building a better product IMHO - Hyrdoflex, Coil, Drew Tang, Stretch/Hess, and CoreVac all come to mind. In the UK/Europe there are bound to be other small guys doing stuff too.
You get what you pay for in the end, and most surfers opt for the cheap alternative - which is a false economy in reality. Better to pay more upfront and have it last twice as long, or even longer....
learn the rules, so you can break them properly