I'm sure I'm alone with this suggestion, but I'd like to see a third option for lairs structures that doesn't include mazes and oblong-looking structures that it takes a master at Tetris to put together in any kind of discernible pattern.

I would like to see underground-city type structures of two types:
- - Dungeon (dank, foreboding, unclean, scary, broken stone structure and walls theme)
Moldy bone piles, treasure piles in corners, dank looks with filtered green light maybe? stone-walls (straight walls) with various accents like missing bricks, falling stone, etc. Murals that look like part of a coffin sticking out, maybe a hand? Large halls that have debris/trash.. maybe instead of a central pedestal a central broken building with collapsed walls and no celing. Machine rooms with broken walls, etc.
- - Underground city (basically the "before" of the Dungeon, pristine walls, shiny floors, no debris besides small dirt piles in corners, partially exposed gleaming chests (in the dirt) as murals, head and shoulder picture of a dragon (one for each color), halls could include a bindable stone structure with parapets and towers (Higher and more intricate with each tier), etc.

I think the bottom line is being able to choose something other than a honeycomb effect for the linking structures (straights, 4-ways etc) would even be better. Maybe another color selection? Definitely square-type structures would be nice for the less-abled planners to make full use of their lairs. Potentially a little different feel to the walls and look for a 4-way vs. a 3-way vs. a bend. That way it's easier to see the flow of a lair when you're looking down a long hallway and it looks like every single connector has a hallway attached to either side.

Another possibility would be to make murals bring the walls in closer so they are straight-appearing from the side. That way it doesn't look (from a distance) as though there is a connecting hallway there.

Just some thoughts.