With PE, one of the greatest maxims to follow is "Don't fix what ain't broke."
You have to understand that PE is a marathon, not a race. If your routine is giving you positive PIs and growth, there is no reason you should change your routine. But, if your PIs start to become neutral or less ocurring, or if your growth plateaus, then I would suggest to take a small break and come back with a bit more force than when you started, ie., 1 on/1 off.
Just because a manual says to do a certain routine for a month before moving on, doesn't necessarily mean you have to increase your routine. Some people have kept the same routine throughout their entire PE career and have continued to grow.
Everyone's penis is different. Listen to the little man. The little man knows all.
My suggestion is to re-read the thread on PIs. If you feel you can increase the workload to 1 on/1 off, then do so. But if you feel the slightest bit overtrained or more sore than usual, then take a break for a week and go back to the 1 on/1 off.
