OK, so, typing this from our gate at MCO. Our original flight time (which everyone wanted to know) was 10:15a. Would have made it with no problem. Joke's on us, we switched to Delta because they had a nonstop, and now our Delta flight has been cancelled and rebooked for three hours from now. So you can have your schadenfreude.
Here's what happened:
--Concierge led us to the front of disembark line around 7:15-7:20 ish (?)
--Grabbed luggage from concierge area (to the left as you come out)
--Through customs in about five minutes
--Feet on the ground at 7:30
--Mears car showed up at 7:40
--At MCO by about 8:30, but I'm not 100% of the time because during the ride over I started getting notifications about our cancelled/rebooked flights, and needed to do new check in/boarding passes etc. on the phone.
Security in terminal B was a walk-on (really, they were moving so fast I almost couldn't get my stuff organized in time). We were at the furthest gate in our Delta wing by 9:13 (took a screenshot). However, keep in mind:
--I stopped before check-in at Delta for about 15 minutes while we re-organized luggage (needed laptop chargers in carryon due to long wait for new flight), chatted with a Delta rep for a while about the implications of the rebooking (would our seat upgrades transfer? (they would)) and how my Delta amex wasn't linked to my flier account. THEN check in, then super-fast security, then the monorail to the gate, and then a fifteen minute wait for Starbucks. And after all that I took the 9:13 screenshot.
So ... take from it what you will. Anything can happen, and early flights are still not 'recommended', but they are also not impossible.