I admit it, I have been extensively raiding Dyson's maps. I tried some other sites, but they just weren't cutting the mustard.
Perhaps I'm very picky about what I want; I don't think I am. It seems to me that a dungeon-generator (of which there are dozens of free ones out there) should be relatively-controllable. But none of the generators I consulted allowed me to do the things I wanted to do.
I'm designing Silvergate in sections. The whole city will be built as a series of areas which can be thought of as something like districts or neighbourhoods, though they're really quite small. A megadungeon built of lairs bolted together, sure, but bolted together in a way that sort of makes some sense, please. And as (at a guess) I need something like 60 of these sections, each with 25-45 (or there abouts) rooms, that's about 2000 rooms all together. A lot of mapping.
My ideal generator would ask questions like 'how many rooms do you want for a given area?' and 'how many exits in which directions?' and 'do you want a) a mix of large and small rooms, b) few large and many small, or c) few small and many large?' - but those I've consulted don't ask those sorts of questions. Just some randomly-plonked spaces and corridors aren't so much use (even if they do come populated from some generators). Fine in theory for a random lair, not so good for a section of a bigger whole that is supposed to hang together in some way.
So I'm back to either drawing the maps myself or taking someone else's. I certainly have drawn some of my own. I will draw more of my own as I go along. But I'm also going to use some of Dyson's maps in the production of Silvergate as a playable megadungeon.
But, Orc, I hear you cry; surely the problem is that you can't control them? If a dungeon generator can't produce the results you want, how can taking existing maps from somewhere else?
Well, even if I can't control them exactly the way I want there are several advantages to using Dyson's maps. The main one is that due to his prolific production, there are hundreds of potential maps to be selected, and unlike a generator where I feed in the parameters and get it to produce something for me, I can see them before I download them, and if something looks useful, I can take a closer look and if I like what I see, I can download it.
There are three reasons really that I'm going to use some of Dyson's mega-delve material: a) they're very nice maps in their own right; b) they (at least some of the time) fit together in a logical way both horizontally and vertically, giving me more coherence about how the city is designed, and c) because Dyson's megadungeon is a Dwarf-city too, and so, why not?
If I find anywhere else that produces maps of the same quality, then I'll use them as well. But I haven't yet.