Jay, - Sorry to hear of your failure to see any difference! - Don't know what else we can do!
Mark's description sums it up well:-
I notice it most in the muscles where the tail and the body join. The rippling of the muscles is a joy to behold, though the occasional flashes from the fins are neat too.
All I can add, is that on my setup, the effect is VERY minimal at very low fps! - When we first started testing MAT, I was getting only ~18 fps, - and the N key had no noticeable effect. As various problems were sorted out, my fps increased to ~44 and the N key started to work it's charms. (but resulting in a slight drop in fps to ~39)
Summarizing, - The higher the fps, - the more noticeable the CalcNormals effect, - and the greater are fps lost after the N key is pressed!
If you can get 35/40 fps with CalcNormals ON, but see no difference, - then it's new monitor/Optician time!
Sorry!