Most of 2012 was doing various hours with the Penimaster Pro. As time went by I was just doing 60 to 80 minutes per session, struggling not to have a swollen frennulum.
In Dec 2012, and now Jan 2013, I can now do 2 hrs to 2 hrs and 15 minutes twice a day. When motivated, I can get a third session in at night. It may have been that I over did things and made my frennulum prone to edema. Just taking things easier for a number of months has things more to my liking. Able to go with longer sessions.
My skin is not as forgiving as it was 40-50 years ago, so I have to exercise caution in length of time I extend.

I do see that my flaccid girth is noticeably increased. When I exit the PMP, it is between 4.75" and almost 5". Normally I don't measure. I am just getting what ever I can get.