$2/device/day. Use a rocket or other receiver to rebroadcast to the boat to save monies.
Reasonable speeds during the day, slow at night. Fairly consistent.
Skype for business worked well.
Verizon via Telcel: pretty bad. 4G until a call was made and then 3G took over for the call. The voice quality was like being underwater. *sigh*. No idea how well a telcel SIM would work.
Tiny. Make sure to give yourself at least 1 hour for the $320MXN cab ride to the airport.