I'm a greeeeeat fan of jelqing. I'd say about 95% of my results came from jelqing, and that includes length gains.
However, I have never jelqed erect, at least 100%. The most erect I've managed to jelq was about 70%. Any more than that I start to feel uneasy with the amount of pressure it creates inside my penis, so I hold back.
Each penis is different and each guy has his own different goals, with some looking more for girth and others looking more for length, so I do understand the need to have specific exercises that target specific gains.
However, in my personal case, I am very much happy with the overal results I got just from jelqing. I have gained length, I have gained girth, I have gained flaccid length and also some flaccid girth.