I think I have booked more than half of my cruises on board and transferred about half of them to a TA.
The reminder I have booked directly with the cruise line or via a TA (50/50).
It was a bit "messy" with the TA last cruise, problems with payment etc. They also refused to take over a booking I made onboard as it was "too far in the future". Never heard of that before, but I think it had to do with the flights, as they were not possible to book that far ahead. That has never been a problem before as I have booked the flights separately, but now they only have packages with flight and cruise.
I will have to look for a new TA.
/Erik