Quite often the scope itself cannot be used as a finder, in whch case a 9x50 is a huge plus. For instance, when double star observing at very high power, once the eyepiece of choice is precisely focused, I would never take it out to use a low power eyepiece in the scope as a finder. In this instance I'm dependant on my finder to help star hop and find my ultimate target.

BTW, not all 9x50 finders are really 9x50. My Celestron 9x50 finder has a 7mm exit pupil. That ain't 9x.

edz