Entropy is right, and I also tried that during this period, I maybe should have mentioned it. The benefits are it stays in your system longer so you get better nocturnals and it is resultantly better for penal health. It also gives more 'natural feeling' erections and is less of the sledgehammer BAM! that viagra can be, and you get less of the unpleasant sides like nasal congestion, headaches, visual stuff etc.
The main negative is that I found as it was 'gentler', I certainly did get a tolerance to this, as quickly as in a couple of weeks.
Thats why in my opinion viagra and cialis should be a 'as needed and only when absolutely necessary' option. You don't want to end up needing it all the time as a crutch.