Can't remember the route name, but I tried an 8b very much like this at a crag called Marche Du Palais near La Turbie last week. Was raindogs like difficulty to an OK rest, to a long and tiring roof section which felt as hard as something like monumental armblaster. Felt like the living end to me, but still got 8b in the topo, probably because there were enough rests to stop the difficulty adding up too much.
If there are no rests, then difficulty mounts up incredibly quickly, whereas even poor rests make a massive difference. Plus, it's loads harder to climb powerful moves after pumpy climbing than vice versa.
moron