That comment moved me to register with this forum (I have occasionally lurked for about a year now) since it resonates somewhat with my own experience. It is now 15 months since my operation and I still leak variably, though I gather the majority are fully continent in about half a year.
In my case nights were resolved quickly, being totally dry after a couple of weeks and not needing pads (there have been just a couple of "accidents"). Daytime was different however and the decline in number of pads per day needed has been slow. It felt like a major breakthrough when I could first get by with just 2 pads and could confidently go out with just one spare in my back pocket. I am now mostly OK with one. I now don't usually experience "stress incontinence" when leakage is associated with actions that raise abdominal pressure such as lifting.
What I experience is rather similar to Nomad's point 4. When I start the day my bladder seems to work well, and able to retain a reasonable volume though not as much as when I went out for beers as a student. As the day wears on though the sphincter gets tired, and I can't hold as much just as described: there isn't enough for me to get a feeling of a full bladder so I am alerted by the sensation of a dribble. Some days the sphincter seems to hold on better than others, sometimes but not always in a way I can anticipate. Doing some gardening last Saturday for example, predictably resulted in significant later leakage,and I rationalise that by assuming the sphincter successfully resisted the pressure on it at the time but then got more tired for later in the day.
Thanks Nomad for describing this, which reassures me I am not alone in the experience. It doesn't seem to be a pattern of incontinence described in the leaflets about prostatectomy.
Speaking anatomically (something I am actually qualified to do) it does probably relate to the 2 sphincters in Nomad's second point. The pelvic floor sphincter that one can consciously contract is restricted to short periods of action, so it is good at adding extra tightness when there is a risk of stress incontinence but useless for closing the urethra for long periods. While you can identify the sphincter by stopping urination mid-stream no one can maintain that for more than seconds. Personally I still persist with the pelvic floor exercises, partly as an act of faith and also with the theoretical possibility that the body mechanisms for building up muscle that is used a lot would also help stimulate the nearby "unconscious" sphincter (the word used technically is involuntary).
In normal men (i.e. those still with a prostate) that sphincter is separate from the pelvic floor since the prostate lies between. It is not something the surgeon can identify in the operating theatre, and it varies in how much it lies in the bottom bit of the bladder and how much in the beginning of the urethra where it is surrounded by the top of the prostate. Thus the damage during surgery is very variable between patients. In Nomad's and my case I presume most of the sphincter was unfortunately removed, and we have a long wait for the little bit remaining to build up its bulk and strength.
In terms of factors to help, the hospital leaflet (and the excellent Prostate Cancer UK literature) warned of the effects of caffeine and alcohol. At some point I got fed up of always having to make special requests in social situations so I did an experiment. In my case I found normal tea causes no problem, making it easy to find something to order in a coffee shop. However if I want to drink coffee, if it isn't decaffeinated I suffer the consequences for about 24 hours. And if you ask for decaffeinated coffee in a restaurant there is no guarantee that is what they will serve, I quickly discovered it is safer to ask for tea! Alcohol deesn't cause me problems, at least for moderate amounts of beer or wine, though I have noticed an effect from larger quantities sometimes consumed at parties without keeping count.
Nomad's experience of changes in urine production probably depends when he eats. While you are digesting food the body keeps an awful lot of liquid in the intestines to help with the process, so that may only start moving to the bloodstream and on to the kidney and bladder two or three hours after the last meal. I don't know whether it might be possible to help things by varying mealtimes.