While diamond may be the hardest material, that doesn't mean it's impervious to wear. Microscopic examinations has illustrated that diamond indeed does wear down over time. If it wears, then what it's in contact with also wears and becomes deformed over time. Consider that the velocities and forces in the grooves is substantial resulting in localized temperatures of several hundred degrees. I mean if something trivial like inserting and reinserting a record into a sleeve causes marring, even if you've never seen the photographs of needles, is it that hard to imagine what happens to the grooves? Consider for a moment that vinyl is not a pure polymeric material. It contains additives, extenders, modifiers, both organic and inorganic that impart usuability and longevity. Hell, doesn't your razor wear simply from shaving? What's the psi generated when a 100 lb model walks on a floor with stiletto heels?
tzucc, I can't force you to try it only suggest that it's well within your abilities and capabilities and apart from time, the cost to you is quite neglible. The benefits are several - the knowledge of how to do it, the ability to 'rip' your vinyl collection and take it wherever you go, providing unlimited copies of your vinyl, archiving, a deeper insight into what makes vinyl different from CD, the ability to 'repair' what may've been a damaged and precious recording, and so forth. By no stretch of the imagination does this mean that your digitized copy will sound the same as vinyl played on another system with a different tonearm and cartridge. It means it'll be incredibly damned close if not indistinguishable from what your played on your system. In fact, you could transfer it to your iPod and play that while you tell your friends you're actually spinning a tune and I doubt they'd know what was what.