I have put so many hours into Destiny...
Yeah, Strikes are prety zen. If you get a rhythm going you can just do them forever. Once you know them better they get closer to 10 minutes than 15-20. Raids are adding more and more song and dance to the shooting. Which is fun, but really, really requires strong communication.
If you're looking for a guild, I'm in one of a trans streamer I follow. Its active in waves.
I'm really interested in seeing where the game goes with Bungie no longer working with Activision.