Yes, I also like the bigger biomes. But since the mountains are not higher than 60 meters at most, they would be more like hills and steep hills. I think they would look a lot better with some trees growing on them. There could still be flat areas with plains, but there should also be some special features in the normal biomes imo. It makes exploring a bit boring when you know exactly how the landscape will look as soon as you see the next biome. Endless taiga forest on mostly flat land, endless grassy, flat landscape, endless snowy landscape with a few hills, endless flat desert with cacti, or suddenly a lot of mountains. The biomes don't blend well anymore either, I think.
If there were some areas within some of the biomes with bigger hills or mountains, it would make them less boring. Especially since they are so big. It makes them too repetitive not to have any significant variation within them.