It's been a while that I grew these and since I do not use the Psychedelic mushrooms I grow I can't say anthing about the specific bitter tast that Gyms have and why so few people actually use these shrooms to have a Psilocybin experience.
For me it was a lovely opportunity to grow something different from Psilocybes and that does contain the magical molecules Psilocin and Psilocybin.
Those are the Luteofolius grows I did:
I also grew Gymnopilus Spectabilis once and strangly only had one big fruit coming off of a usual bag culture.