I am glad i didn't read the reviews before i booked with Maya'ch Expeditions. I really had no issues with them. They drove from Antigua to Coban safely in rain in less than 6 hours with a stop in a nice rest area. Then we did a day tour to Semuc with them. The guide was good and spoke good English, did some extra activities like diving in a tiny underwater cave in Semuc ( i bet many didn't even know about it). Even helped to carry a 3 year old kid to the observation area.
Next day also used Maya'ch shared shuttle to go to Flores.
Yes, the shuttles were usually 15 minutes late, but it's expected when they pick up in a few places and drive you door-to-door. Also not the newest buses and A/C usually off but i kind of expected that in Guatemala.