Opinions on hard anodizing and TiNi coatings?

[simplechamp]

Is there a general consensus of how much these coatings help on wear items? Will spending the extra cash on upgraded TiNi or hard ano'd parts make a big difference in the long run?

For example, if my diff ring gears are already made of hardened steel, will using a version with TiNi coating really make them last much longer?