I think a better idea would be to have the level size increase with danger level (with randomness playing a part, of course).

I wouldn't necessarily tie it to danger level, since size doesn't need to equal difficulty... a very small level packed with emperor liches could be maybe even more challenging than a larger level, since you won't have anywhere to escape.

Maybe level size could be tied to theme, for example a tower would necessarily have many but small levels, while a cave could have less, but larger levels (depending on the nature of the cave).

For "default-themed" dungeons, if there is such a thing, I'm actually quite fine with the current randomness. I agree maybe the average size could be made a bit smaller but I wouldn't change it radically. Bigger levels can get somewhat boring right now but we have to be aware that there are a lot of missing features. When those big levels get packed with traps, locked doors, dungeon shops, special rooms, more varied monsters/items, pools, etc. I don't think they will be tiresome. And if they are, then my preferred solution would be to add more dungeon features to make them varied, rather than make them smaller :)

I should have clarified that the level size tied to danger level would be for normal, generic dungeons. Special dungeons, etc, would naturally have their own rules.

Think of it this way - like with maze levels, there would be various random level designs that are "special", and many of these could have preset or otherwise special sizes. A small level packed with high level monsters, not unlike the Dwarven Halls, would be one such special type of level. Special dungeons like a pyramid would similarly have special patterns controlling level sizes. But if you enter a random, generic dungeon, and a level is just an ordinary, generic level, then the size of the level should vary with danger level.

Mind you, randomness should also have a significant influence, as I said. As a simple example, perhaps at danger level 1, the level will tend to be about 60 spaces left/right and 50 spaces up/down, with a scaling factor of up to 1.5 either way (so, between 1.5*60 = 90 and 60/1.5 = 40 for left/right). At danger level 11, perhaps it will tend to be more like 90 spaces left/right and 80 spaces up/down, again with that range playing a role, meaning that the range for left/right would be between 60 and 135 spaces.

Obviously, it's a very generic way to put it, and very arbitrary numbers chosen to demonstrate.

Another interesting idea would be to have dungeon branches smaller than levels of the normal dungeon. So, if you go from dungeon level 1 to level 2A (with 2B being the other branch), 2A will tend to be about half the size of level 1, and then level 3 will be a normal size again. It would give more of a sense of consistency.

Go to (selected location) command would make it less tiresome to move around in bigger levels. I don't see any other problems with them.

Ultimately, the importance of the size of the dungeon will depend on food availability and time-dependent factors like ADOM's corruption? Otherwise the new JADE shortcuts make navigating dungeons pretty straightforward.

Already implemented for 0.2.0. Forgot to change the issue.