With BB rows-unless there is a previous injury, the lower back strengthens itself and stops feeling like the focus of the movement very quickly(2-3 wks IMHO and experience). I went about it by utilizing 10x3's until I was well past the "hump" (10 setsx3reps just to be clear).I was able to maintain proper angle and execute complete reps in away that (when new to the movement) I couldn't using a higher rep scheme. Also the load possible in a 3 is almost staggering in comparison to what a lifter would be using in say a 10 or 12, and because of this, strength gains came in leaps and bounds.
Currently (on a good day), I can and do row more than my bodyweight with precise form and with steady controlled movement (no jerking or "almost completed reps). With less than perfect form , altering the angle to a more "Dorian Yates approved" (did anyone get that there's a joke there?) pitch I can go substantially higher almost to completion for a pointless for anything but ego single rep.
This is not to brag, but to show that my experience with breaking thru the initial lower back "feel" may have some value- I only do 4 exersizes (bench, military press, BB row, deadlift) so I take each one very seriously as I can't afford not to.
A back built on JUST pull ups/pulldowns seems flat and "hollow" to me, no matter how wide; obviously the best bet would be to do both rows and a pull.But if like me you are doing a "simple" (LOL!) routine, and are picking from the two , IMHO- rows are capable of developing width just as well while giving a full ,thick, and powerfull look to the entire back.
Let me end by saying that i'll be 40 yrs old this year, Quad (IMHO one of the most inspiring posters here), has 13 yrs on me , when I'm 53 I very well might not be so enthusiastic about rowing either, depending on how my back weathers the almost decade and a half to come!!!
From the looks of his avatar whatever he IS doing is working just fine!