Pretty sure yes. Maya have left me standing on a number of occasions, and that's never happened with Tropic. I have flown into Belize very late and well after dark and assumed I'd be staying on the mainland that night, but when i walked through to the local airlines booking room there was the Tropic desk still operating. Maya had gone home. Tropic put me on a flight to San Pedro that didn't take off until after 8:30pm, and I was the only passenger.
On another occasion I had booked on Tropic for the second to last flight of the day, after a shopping visit to Belize City. I knew I was going to miss that flight so phoned them; the last flight of the day was full, but they told me to turn up anyway. I did so, and three of us ended up on a plane that left maybe 30 minutes after the last scheduled departure. Furthemore, I had bought a bicycle on that trip and they dismantled it and carried it without a murmur and at no charge.
By contrast, I bought a round trip ticket from San Pedro to Dangriga with Maya, with booked aircraft. When I returned to Dangriga airstrip, there were four others waiting for the plane to Belize City which I had to board to catch my onward flight to San Pedro. The plane was sitting on the tarmac in front of the terminal, and there it stayed for 2.5 hours. There was nothing wrong with the plane - they simply said it weould be uneconomic to fly just five of us. My would-be travelling companions were furious, as like me they had onward travel arrangements. What should for me have been a 55 min journey ended up taking almost 4 hours. When we did finally fly we got on the plane that had been sitting there for so long, which is how I know there was nothing wrong with it.
I have an even more blatant example. A friend who lives in San Pedro had to go to the US, to Philadelphia. She flew from Cancun to Philly and flew from Belize to Cancun on Maya. She bought round trip tickets for both legs of the journey, with confirmed reservations. When a few days later she returned from Philly to fly on to Belize she was told Maya weren't going to operate the flight that day as there weren't enough passengers, "but her ticket would be valid for tomorrow". She ended up having a 5 hour bus journey, an overnight hotel stay, two taxi rides, and a (shorter) flight with Tropic, with an overall 24 hour delay. It took her several weeks to get a refund from Maya, who wanted only to give her a credit. Guess who will NEVER again fly with Maya.
I am in absolutely no doubt. Fly Maya if you don't have a schedule, have cash and want to save money (30% or even more). Fly Tropic if you want to be certain of getting there.
Perhaps what you surmised above is true, that either airline will put you on the next flight "assuming there's room". But that flight (probably) won't go if it's not full and it's Maya, whereas even if the plane is full Tropic will (probably) get you there, on your own private plane if necessary.
"You pays your money and you takes your choice".
