Hello Andy,
I can only report what has happened to me, and I'm not sure if it is representative... but here goes.
Started ADT June 2011. RT in October-Dec 2011. Stayed on ADT until January 2014. (2 and a half years in all). It took all that time for my PSA to reach less than 0.1.
PSA stayed at "less than 0.1" until January 2015, and it is now 0.1. That's the good news!
I put on about 15lbs in weight over the time on ADT, nearly all on my Moobs, Stomach and "love handles". My arms and legs got thinner. I experienced all the usual ADT side effects, but fortunately as I have always eaten little sugar, I stayed clear of Diabetes. I had no energy, and stopped nearly all exercise. I hoped everything would return to "normal" in a few months when I stopped ADT: but it was not to be!
In Autumn 2014, I started to try to exercise a little more, but was so breathless, I ended up with chest pains. My libido remained at zero, and I had no erections. Over Christmas, I decided I needed to take matters into my own hands, so started dieting and exercising. I was walking a few miles most days, and the chest pains started to go. I went on a low carb, low calorie diet. As my diet is dairy free already, and also no red meat, it was a challenge. However now, 3 months later, I have lost all the extra weight, and I should have more energy. Unfortunately the chest pain was diagnosed as Angina, and as I had a ruptured peptic ulcer in January 2014 that required emergency surgery, I couldn't have a stent fitted as the blood thinking drugs were too risky, so I am now on Statins, Beta-blocker, Blood pressure pills for the heart problems and Omeprizole for the ulcer......so have no energy as the beta-blockers restrict my heart rate down to about 60, and blood pressure under 100/70.
I still have no libido: In January my Oncologist said that it would take at least as long as I was on ADT for it to return, and there is a reasonable chance it never will! However, I do have a better body shape and I am not so emotional, so something has improved! I have not regained any body hair either.
I guess I have accepted that this is now the future, and if it does improve, it is a bonus. Sorry not to bear good news, and I hope your experience turns out much better. I guess I have realised it will not get better by itself, just because I am off ADT. I need to take action to improve how I feel.