Really, it's a two part question:
(1) For those of you who had a radical prostatectomy, how many have recovered to where an erection capable of penetration without pills, needles, implants, etc has occurred?
(2) If you have recovered erectile capability, was it an "overnight" event, or are there signals along the recovery process that indicate functionality is returning?
Question 1, is to get better data than that presented in Mulholland's book (Saving Your Sex Life, p.68) which cites 22 studies from 2000 to 2007 where results vary widely. Patient numbers per study ranged from 42 to 25,561 (mean/average 1,646 patients); percent "capable of having sexual intercourse" ranged from 12% to 96% (mean/average 48%; standard deviation 25%).
Question 2, is for yours truly to be on the lookout for something positive happening "down there". Waiting 12-24 months (post surgery) for results, to me, is bullshit guidance.