Hi Jason,

I'll compliment Nick's reply with some historical perspective. Way back when we developed MapIcosahedron, we used ld141 because the vast majority of edges were smaller than those of the densest surfaces we used, those from FreeSurfer. So, the idea there is to preserve any detail present in the original meshes. To get information about the mesh you are viewing in suma, open the surface controller and click on 'More' under surface properties. The info is more for debugging purposes, but it will do for the occasional parameter. Otherwise you're better off with command line tools such as those in PyMVPA or the Surf* programs in AFNI. Depending on the amounts of distortions in the sphere.reg some edges can be considerably longer than the average in the standard meshes, so there is some risk of undersampling in those regions. For most analyses, particularly FMRI, ld141 is overkill. But because we estimate the smoothness of the data (SurfSmooth) in our analyses (the noise in the data to be precise), oversampling is not an issue. It is just more processing time, and as Nick points out, the meshes look better.

cheers,
Ziad