More Mega-Dungeon Maps

Well here are the maps for levels 2, 3, and 4. I was not happy with the way I was stocking level 1 and have had to restart that. I am also in the process of drawing level 5. Level 2's map is 95% done. Levels 3 & 4 still need some work. 

Question- Are these maps close enough in design to be "related" but different enough to not be rehashes. Any suggestions on improving them?

LEVEL 2

LEVEL 3

LEVEL 4