There are several other factors that would play a role in my choice. As to your platform, how wide is it? Is it fixed or does it lower into the water?
How far off the water is it? What size crane and how much weight do they figure in addition to the crane?
Generally I prefer a crane. However, that does sacrifice a good bit of space on a boat that size. Plus, I'd want the biggest rib possible. It seems that would be 10-11' on that boat, plus I'd want a decent size outboard. If either solution prevented that then I'd be looking the other way. We use our RIB too much to go smaller with it. Our personal preference would be a 12' jet RIB but that would not be for most.
Still if my crane is too small or my space up top too small, then I think less of that choice.
On the platform or davits, I don't want the dinghy wider than the platform. I also wouldn't sacrifice length because of boarding needs. I'd prefer a platform that lowered into the water and then just using chocks instead of a davit. That also requires it's high enough not to be in the water when running.
Either solution can have docking challenges. A crane needs you to dock on the right side if side tie and really struggles in a slip. The davit isn't so good in a side tie situation if many boats are packed tightly but great in a slip and good in most side tie situations.
I know I haven't provided answers, but hopefully some points that will help you figure them out.
Next I would want to know what they've installed, what dinghies have been used and how they're worked. You've got weight on top vs weight hanging off the back. I've seen boats in that range that really struggle with added weight behind the stern.
I wouldn't want to be doing something different than others have successfully done. I have only seen crane used on that specific boat. Now perhaps you'll gather other information. If not, I'd lean strongly to the crane.
