I ran a playtest of Pathshoe (a new Pathfinder + GUMSHOE hybrid from Pelgrane Press) for my gaming group last weekend. I have several of the other GUMSHOE games (Mutant City Blues, Esoterrorists, Fear Itself) but haven't run/played them. We had a bit of a problem with figuring out what skill uses and spends should be prompted for by the GM versus asked for by the players.
In a given scene, you might have a core clue, some no-spend optional clues, and some spendy optional clues. But in the end it's not clear to me how much prompting is supposed to be on my part.
It seems like you're encouraged to give the core clue automatically to anyone that has the skill. "We investigate the crime scene!" "Okay, who has... Forensic Pathology? Two of you? Uh, who has the larger pool, I guess? Pat? OK, Pat, you determine the guy died of autoerotic asphyxiation." Mostly GM-initiated.
But then the optional clues are less clear. "Forensic Entymology will show that the maggots infesting the corpse are actually from New Jersey." Do I just ask for who has FE and give them the info? Or do the players just run a fishing expedition where they say ad infinitum, "Does Streetwise tell me anything about the area? No? Does Forensic Dentistry tell me he's really a vampire? No? Does Forensic Entymology tell me something?" "Ding!"
And then with spends, it really seems like you have to prompt, but how explicit are you? "Anyone want to spend 2 points of Literacy for... a clue?" "Yes?" "He has a bunch of tattoos in Latin that says 'odi profanum vulgus et arceo' which means 'I hate the unholy rabble and keep them away.'"
It seemed at times that I was just handing out all the info to everyone because they had all the skills covered. But I'm not sure how these exchanges are supposed to go.