Just came back today (had a great time, btw) and ME for the return trip wasn't very good. First, they couldn't print our boarding passes for some reason, even though we were on United (one of the participating airlines), which meant they couldn't check our bags, which in turn means needing extra time at the ticket counter. Then, our 8:15 AM bus disappeared into a black hole, it never showed and when the 8:45 driver showed up he had no idea what happened to our bus. Fortunately there weren't many people taking the 8:45 so we all fit. The driver (a very nice man) radioed his dispatcher to find out what happened for us (not that it mattered at that point, other than just satisfying the 8:15er's curiosity) and he said they told him either the 8:15 bus was never dispatched, or the bus broke down (they didn't know if one of their drivers was stuck on the road somewhere or not????).
So anyway, we didn't get to the airport until 90 minutes prior to departure, and still had to check two bags and get our passes. Fortunately the ticket counter lines weren't long and we had no problems checking in (we had a snafu on the way to Orlando that took 45 minutes to fix, if that had happened again going home we'd have been SOL). The wait at security wasn't bad either, and we even caught a tram just as it was departing to our gate area. Even so, we only made our flight with about 20 minutes to spare prior to boarding.
ME on the way down was perfect, I'll be happy to do that again. In the future, for returning to the airport, I think we'll take a cab or a town car instead if we have bags to check. We like to be at the airport super early in case of problems like we had at O'Hare at the start of our trip, or even just super long security lines. I'd only use ME for a return trip if I was only doing carry on.