Here's the deal, a grid ignores any irregularities inbetween grid points. Our SOP is to basically shoot a grid based on the scale of the final plat PLUS any and all "breaks". Shooting purely a grid can totally miss a drainage ditch or other major break features. Same result when you base your surface on a grid.
Grids are only good in FLAT (read that as "paved") areas and can give only a rough solution to the surface that should only be used for estimates. In 44 years of compiling contours, I have NEVER done so with a grid only.Grids are for Engineering rough estimates. Tins are for cartographers. And Trix are for kids!!