I believe that a good smoked paprika can enhance the flavor in some relatively subtle ways, in certain situations... It's my understanding, that paprika is made using 'sweet' peppers, not hot ones.
I believe that too much paprika is a bad thing, and many rubs and/or cooks use too much of it at times. I actually stopped using paprika for a long time, because I started to dislike the taste, I'm slowly coming back around to the point where I do use it again, but I personally am much more careful about how much I use.
But, then I dislike BBQ that has too much rub on it... Never understood the need for a binder, because IMHO, if the external moisture of the meat itself isn't enough to hold the rub on, then you've put too much rub on .
Public Service Announcement : Just say NO to too much paprika !
( Side note... I'm with Bentley , I think that paprika is often used as a filler )