When I use surface by boundary options, I have in the surface by boundaries form, the sing trimmed patch. So, turn on or off this options I get different surfaces.What's the best options considering curvature and tangency?
I guess that depends on what you are going to do with your model. If you are going to do some finita element analysis of your model and the surface you are creating is small compared to its surrounding I suggest creating a single surface rather than several surfaces with tangency. This way it will be easier to select the one surface rather than several.