We did Mears for our last trip (family of 5) and will not ever again. There is absolutely nothing "magical" about it. With some limo services (which would pencil out cheaper than Mears for us) they will even make a stop at a grocery store so you can stock up for your trip. The savings there over delivery makes any difference worth it.
To answer OP though - TO WDW I think we had one stop before us - not bad. It was the return to the airport that turned us off. We were asked to be ready in front of our resort, what turned out to be over 30 minutes before we even got a text that the bus was coming (Mears set the time in an email). Mind you, this had us standing out in front of our resort BEFORE 6a. It was a good 45 minutes before the bus actually picked us up. We then boarded the bus, no apology for being late. Imagine for a minute if WE had been 45 minutes late getting to the bus - The bus would have left us stranded and we would not have gotten a refund, and rightly so, right? The bus then stopped at 3 more resorts before heading to the airport. The driver played, not Disney content, but Christian Rock for the entire trip.
We wrote to Mears to complain and got no response. The silence spoke volumes - we are done with Mears, and will continue to relay our story to any who will listen.