I am curious as to what are the subtle differences between these two boss extrude methods and overall what the difference is in my part, whether I extrude up to surface or up to body. I know "up to surface" takes a surface as an input and "up to body" takes a solid body as an input. However, while trying to model the Model Mania 2011 phase 2 part, I was seeing aesthetic differences between the two methods.
I have attached pictures of the two parts using each method to show the differences in appearance. The red arrow points to the area of concern. The main issue comes when I add the final fillets to the vertically extruded cylindrical hole things. I don't know why the fillet looks different when using the two methods.
I have also attached the two versions of the part as well for anybody who would like to open up the part. The only difference between the two .SLDPRT files are the final boss extrude. One extrudes up to body, and the other extrudes up to surface.
Any thoughts or opinions would be much appreciated!