TBH, I wouldn't see it as much of an "amazing, amazing incentive". I'm not even sure I'd take it up.
3 days of enforced training & group activities while jet lagged, sandwiched between two full days of travelling.
It's the sort of gig I'd consider turning down as a freelancer, even though I would actually be paid good money to be there, as well as travel, accommodation and meals...
If I was doing it as an employee (also being paid to be there), it's one I'd seriously moan about.
The fact that they are 'blown over' and 'grateful' says a lot, really.