I had DaVinci nerve sparing in 2005 at age 58. Never really had a problem with ED but I took advantage of the situation to try all of the pills. Didn't care for most because of the side effects.
Then my uro suggested Cialis (5mg) for daily use. Now at 66 I feel like a 30something in that department. Love the stuff and no side effects that I notice. And no need to plan ahead. How many times have you popped an expensive pill only to have your "plans" go south?
I recommend it highly, even got some of my non-PCa buddies on it.