I would say use whatever the manufacturer advises.
I have had a roller trailer under my boat for many years with no damage. In my boating environment, a bunk trailer would be a pain due to shallow ramps. The trailer has 24 rollers and the boat weighs approximately 4100 lbs. Just had it weighed, the weight ticket was 4960. I could probably add a few more rollers, but it has been fine the way it is.
My brother had a similar size boat on a bunk trailer, and I found it to be a pain to use, even on the nice steep town ramp. Winching up the boat was a chore, the roller is much easier. Roller trailers are more common here than bunk trailers due to wide swings in water depth with the tides (approx 6').