Perhaps I am overlooking the obvious, but there are a number of places in the R9 that must be lubricated properly with grease, as shown in the sticky post.  
I feel certain that just having a coated slide cannot "self-lubricate" the entire gun.  Presumably, there will still be lube requirements necessary for the longevity and reliabie functioning of the gun.  
That being said, I do think that the black finish will be complimentary to the appearance of the R9