This was the torso angle that Dorian Yates liked to use for his curl-grip rows, but I've found that rows done in the Smith machine hit the upper back a little better than barbell rows. They really allow you to contract the upper back hard.
The Smith machine automatically keeps the bar in a very efficient path, so there's no energy wasted in trying to keep the bar close to you like with the barbell row. You can focus on the execution more intensely. Do 3 sets of 8-10 reps.