In reply to harold walmsley:
I started bouldering in Font, and apart from Offwidth I probably have the most experience of climbing low level Fontainebleau circuits (on this thread!), so for me these are the benchmark grades. Yes, there are sandbags. Some areas seem to follow a different internal logic. Some circuits have the same grades as when they were put up and are now polished to a high sheen.
Whenever I climb elsewhere, normally in France but also in the U.K, I'm surprised by how easy the low level stuff is.
I remember being nervous about going to Targasonne because the lowest graded stuff was all 4b/4c. I was struggling on 3cs at the time. When I got there I found out that 4cs were easy onsights.
The only place I've ever bouldered in the U.K is the Peak, and it's the same story. I climbed trad a long time ago, so my recollections of British Tech grades are hazy, but shouldn't short safe 4s have UK 5b moves on them?
Maybe I'm better than I think (I doubt it) but I'd debate if any 4s I've climbed outside of Font have moves on them that hard.
It's easy for me 'cos everywhere else I climb my grades jumps. I've been trying a 4c slab at Rocher fin for 3 years, it just doesn't compare to the grades outside Font.
If you want to push your grade in Font stay off the marked circuits or stay out of the main forest.