I'm rooting for this to succeed. I have a lot of respect for MJ and what he's trying to do.
That said - ticket sales for Kingston looks ABYSMAL. If you go on to the Grand Slam Track site, probably about 75% of the reserved seating is still available. It's going to be awkward when they hold the inaugural event in a stadium that's basically empty.
This is one of the problems with the 3 day format. A meet like Weltklasse or Bislett games or Monaco is a single day, and 3 hours long. The stadiums sell our every year. With GST you're spreading the crowd out over 3 days.
Hopefully they can get people to attend, but I'm not sure how many non-Jamaicans are making the trip to Kingston this weekend to watch the meet.