"Thinking it over", I hope the extension to McCOy works out. Maybe it's too early to be concerned, but I do have some after my Thursday Feb 22 joyride.
While I never got to make a head count on the 840A Boca departure (can't you simply share your train numbers with the public, Brightline?), I did on the 4P departure from MCO - 99 passengers.
That loading is indicative of I know not what, but it seemed "light" to me. Apparently, the additional stops at both Aventura and Boca "pull well". Can't speak for Aventura, but I concur regarding Boca. Towards that end, I think Brightline should establish Treasure Coast stops such as Hobe Sound in Martin (CR 707 & Dixie Hwy looks good to me), Stuart in St. Lucie, Vero Beach in Indian River, and wherever in Brevard. One thing all have in common is "smell the money", which means people flying in and out. This could get Brightline in the game for handling passengers to these moneyed localities from MCO. True, the schedule will need be lengthened, but these are fare paying bodies being handled by "limos" or family.
I'm not sure to what extent the Brightline station located in the Satellite Terminal C with its collection of "what's THAT airline" neighbors hurts business. All the ground transportation options appear to use the original Terminals A&B. That's a "hike", albeit well marked and a people mover ride away. Now to what extent will people "do the theme parks" without an auto, I know not. All I know is that for me and the three hours between trains, I rode "peasant" (only a buck for Seniors; two otherwise) down to the Lynx/Sun Rail station where I saw #91(21) going by. Also wanted to see if I recognized any structures from when I was in Orlando during '56. I did; one-time Greyhound Bus and the Grand Bohemian Hotel, but not much more.
Finally staffing. I can't believe the number of people they have - including security and platform guards to message "don't even THINK about railfanning here (I'm not "hard core"; just wanted a photo of the engine)". How long will it be until the station concessions fold up, as they didn't seem all that busy?
So I wish Brightline well; it's here to stay, but the open question is for how long in the private sector? All told, this joyride cost me $376, but from what I understand, one could easily go through that, per head, in a day - considering all the "extras" they reportedly now have - at a theme park.