Agree with Scott. For most towing around town, the scissor type work pretty darn good. The ability to set the boat down on flat ground and pull the trailer out from under it opens up a lot of possibilities, and servicing (tire pressure, wheel bearings) a trailer with that ability is about as simple as you can get. OTH, you do need to pay attention when pulling one. They can be tippy if pulled in a thoughtless manner. The bunk type trailers need more water to launch, and carry the boat much higher. Pulling a 'toon on a scissor type trailer is like pulling a parachute at highway speeds. Pulling one on a bunk type trailer is like pulling an even bigger parachute!
Difficulty to load and unload would be similar to my way of thinking, assuming you have a nice deep ramp to work with.
I've pulled a scissor type for the last 40 years or so, from Florida, all over Michigan, and the Great Lakes area of Canada.