Do you mean bunk trailers vs roller trailers?
If so, go for rollers every time. So, so, so much easier to slide your boat off rollers. In fact I'd say it's impossible to slide a boat off a bunk trailer into the water. With bunks you really need to float the boat off and onto them, which requires fully submerging the bunks first - not ideal for the trailer chassis.
With rollers you can tippytoe the trailer up to the water's edge to just get the tyres wet, then simply push the boat off the rollers by hand and watch it glide in to the briny on it's own.
However if you're referring to something else entirely then feel free to ignore me. 🤦♂️🤣