calling every zone too hard .... makes this hard to agree with.
I find that the swamp, for example, is probably the best biome... its a challenge, which the black forest only barely accomplished, and it has a resource worth getting loads of, which the mountains badly fail at and to a lesser degree the mistlands as well. That leaves the plains and the swamp as the best for me, with honorable mention to all biomes except mistlands for beauty and variation. I think its OK to have the mountains be a bit of 'go there get silver and done' sparseness because they were never the final biome available. Making the mistlands that way feels like 6 months of derp coming our way, though. I mean I will hit it for some rabbit & marble and things here and there, but not often. Ive got what I needed, and the mist & mountains annoy me.