I have to say, I really love this adventure module. It's a very nice read. The Mythos entities and the story befit each other, there's plenty to spark players' imagination, well-described. It just left me with the impression that the author had a good grasp on Lovecraftian storytelling. I certainly would like to introduce some players to this one, kudos!
In a departure from standard rules, all clues require a spend. This has one advantage - some investigators have similar skills, and no one can hog the spotlight forever given this little scenario rule. "Driving yourself crazy" is also a departure from the standard rules, and I'm not sure how that would play out - it could add to the fun or kill the entire atmosphere of the whole game. Best go with what you think suits your players, it's optional after all.
A little oddity is the selection of investigators coming with it. As this is no conversion product, but made for Trail of Cthulhu, it kind of surprised me that the investigators did not seem to match the rules. There's 3 female investigators vs. 2 male ones, which typically requires creating more investigators. The distribution of skill points seemed a bit arbitrary - the nun had the best credit rating, and almost none had their required minimum rating. Also, the naive, amiable nun was streetwise... Similarly, the alienist had no psychoanalysis skill, and also no first aid skill either (but Medicine at 4). Equipment was left out, too.
I liked the conception of the investigators, though. The descriptions were top notch, I would love to play the "synaesthetic composer" in a roleplaying game. The idea is definitely a keeper and well thought out.
So, best build your own investigators for this one (it doesn't take long, anyway), you won't regret it. Or go with the ones included, their "faults" will hardly impact gameplay, I'd guess.
The adventure module itself, the artwork, the basic concept, the ideas, the writing certainly will reward your spending, and for currently 6.95US$ (or less in a bundle) it's well worth buying.
[4 of 5 Stars!]