I came to realize that my back routine is rather insufficient for my goals. I would like to improve it and put emphasis on wide v-shaped lats, but I am not sure if it is better to focus on wide grip pullups/pulldowns or heavy rows on a machine where you are firmly seated and you can support your chest on a cushioned surface(http://www.beginnertriathlete.com/cms/articleimages/826/Seated-Row-Machine1.jpg). My initial thoughts were that there would not be that much difference in lat activation, so I should just choose the more comfortable one, which was the row. I also liked the fact that it would be good for the rear delts and the traps. On top of that, I felt that the firm seated possition helps me do a good concentrated high intensity pull. The problem is, I never really feel the lats on the next day even if i go hard, whereas one set of body weight pullups (about 15 reps with about 85 Kg) is enough to really make me feel my lats on the day after. This makes me wonder if the pullups/pulldowns are not the better choice. Not because it hurts more the next day, but because with one set only, i can tell it taxed the lats a lot more than my whole row routine. Yet, oddly enough, I remember reading about some experiment with electrodes, which showed that rows tend to activate the lats more than pulldowns. This makes me quite confused. Whatever is better, i would also like to know why. I reckon the pulldowns/ups might have a bit more range of motion, and the direction of arm abduction might reduce trap and rear delt involvement which would likely put more load on the lats alone, but then again, it would seem that the pulldowns activate a lot more of the pecs. Sorry for the long post.
I think you'll find over the long term, that one exercise is no better than the other at building the "V" shape you're after. Having said that, I'd add that we all tend to have one or more exercises that tends to really work for a particular body part. That's just part of genetics and being an individual. I would stick with what works for you while cautioning you to make sure to add variety into your training. It's far to easy to plateau doing the same movements day after day. If you cycle your routine on a regular basis, you may find you'll make the gains you're after.