I'm giving them a test just now.
Perfect world seems nice, I'll add that
Erebus Continents is broken, so that's not going in. Twice in a row, I've tried various different sealevels, amounts of jungle, tundra, desert, etc, but all it keeps giving me is a vast mapwide grassland field, with only rivers and 1-tile lakes dotted around. no peaks, forests, plains, jungle, tundra, etc. Even at High sealevel, it gives no sea. Perhaps it's just not compatible with FF somehow.
Mountain coast generates some oddly artficial ranges/landforms, but is nice nevertheless.