Everyone is different because of genetics and other factors. It depends how dedicated you are and how well you adjust your routine to fit you. Make sure you study A LOT. There's a lot of pitfalls that can either get you injured or make your PE attempts much more difficult.
Personally, I was injured when I tried the JP90. I followed it to a T. Nothing major, just a burst blood vessel, but it sure scared me away from PE for a year. I came back and did a lighter routine, and STILL got a very minor injury. It wasn't until I cut out manual stretches completely (I just use the Phallosan Forte now) that I was able to get into a groove.
Jelqing for a short amount of time, with a low erection level, and light grip can go a long way for EQ. I'd start with just 2 or 3 minutes and work up from there. I'm more of a noob, though, so what do I know?