We have used ME twice and it's the way to go! First time we took it last year, we were at CSR in less than an hour of our plane landing (that included waiting 15 minutes for ME to depart). This past trip in January, we had ridiculous luck - our flight landed 25 minutes early and arrived at 8:05 instead of 8:30am, we walked directly onto ME and immediately departed with only 2 other families on it. By 10:00am we had already checked into our room at CR, freshened up, grabbed a quick bite at Contempo Cafe, and we at MK by 10:00am! Couldn't believe our timing & luck! 
I'm not sure if this is correct or not, but it was my understanding that ME departs every 20 minutes regardless if the bus is full or not.

I'm not sure if this is correct or not, but it was my understanding that ME departs every 20 minutes regardless if the bus is full or not.

look.