The Seclusium of Orphone is a book about wizard's tower style dungeons.
It is full of really good and often original ideas about rooms, items, creatures and NPCs.
These are, unfortunately, organized into fairly poorly designed tables and lists and multiple choice locations that make the creation of these dungeons harder and slower than they need to be while not gaining a lot from being presented in that format. And this is coming from a guy who loves tables and lists, and multiple choice locations.
So, as a compendium: Awesome!
As a tool: It needs a lot of work.
Most of this is because of stuff I said here or here. But the TL;DR is below:
Basically dungeon creation is set out here like character generation, and as a wise man once said character creation should be slow but interesting or functional but fast. Seclusium swerves violently from the mundane to the magical and (unfortunately) back again over and over--I can see most readers starting off going "I'll use these rules to make a dungeon, that'll be a fun way to kill some time!" then after the first one, or (more likely) a quarter of the way through the first one, taking scrupulous notes on whether the guest rooms are "spartan and bare" or "tiny and cramped", going Fuck it and skimming for ideas and then putting it up on the shelf next to The Dungeon Master's Design Kit and the Central Casting books and every other GM tool you wish someone would read, scrape, and Abulafia-fy to save you time.
When the options on the tables are interesting (which is gratifyingly often) the separate versions don't usually have a pressing need to be in a table or list and don't seem to use that format to their (or the GM's) advantage.
When the options on the table are mundane but essential, the formatting of the tables is too slow for the time it takes to roll on them or choose them off the list to be worth it.
These seem like the kind of random tables that work the way people who hate random tables think they work. "Door opens: 1- In 2- Out 3-4 Pick one".
Also, if it was going to take this slow step-by-step approach, it could've used a worksheet or some other original graphic device to help take all the dozens and dozens (and dozens...seriously) of answers you'd have to give in order to go through the dungeon-making process into a thing with a map that the GM could actually look at and use at the table. If you're gonna hold my hand fucking hold my hand, guy.
(UPDATE: The book claims one of the multiple-choice-dungeons can be done in a half hour, so I tried it. No way. That's not even enough time to answer all the questions, much less draw a map and key it with your answers. And I don't write slow.)
I could go on and on about the format but this is actually a pretty cool book so I don't want to spend much more time bitching about it than I have to.
It also contains some quick rules for making LOTFP (or any other old-school D&D or D&D-like game) less trial-and-error and player skilly and more about character skill and some good but fairly blog-standard dungeon-running advice, if you're into that.
If you want dungeon ideas, you should buy it and you should read it, but afterward you'll probably want to raid it more than use it.
Which is fine and good but a bit of a shame--there is so much worth raiding in RPGs and so little worth using.
Footnote: I've seen a draft of Jeff Rients' "Broodmother Sky Fortress" and it looked to be this format of fill-in-the-blanks walk-you-through-it dungeon done right. Though in terms of raw number of usable ideas, Seclusium is perhaps its equal or better.