I just remember Shawn's dimples on his 23 hull from the roller trailer, I have yet to flip mine and see if its the same or not. Makes sense since each roller actually only has a couple square inches of surface contact to the hull, where a bunk would be significantly more. However I have never loaded or unloaded with a roller trailer so I can't say how great they are, and how beneficial a roller trailer is!
I do plan to add bunks under the main engine stringers for more support since the boat will see many miles on the highway.
If its cost savings I would think the wood would be cheaper, but even spraying a bit of paint on all the old ones and replace a couple every year would be better than a big hit upfront.