the key to most upper back exercises is the range of motion, especially rowing moves. Standing, seated, bent over...its all about extending the arm and shoulder all the way forward, and all the way back.
I usually use a Smith machine for bent over BB rows, mainly becuase my gym lacks a more appropriate space or adjustable cage. I find a pronated (palms down) grip easy on smith, and supinated (palms up) grip very awkward, simple due to the fixed plane of motion that smith machine has. with that grip you really need the barbell to be free moving so it can follow a slight arc. I'd also argue that grip pulls the biceps more into play, much like a 'palms in' pull-up vs. palms facing away from you on a pull-up.
regardless, i think from your description you ARE followiing the full range of motion.