I've been using on and off for 3 years.
I feel like we could make a pretty accurate statement that the length of time you're on will effect how easily you come off. A year is better than three years, ect.
I think part of this is due to age. Let's say you get on at 24 and come off at 28, you're most likely going to come off better than a guy who went on at 36 and came off at 40. If you were naturally going to be a candidate for TRT at 40, then coming off the sauce at 40 is probably going to leave you with an undesirable level of testosterone production.
I think this is what makes it so difficult to predict what's going to happen when we finally decide to ditch the gear. There are so many variables and we have no ability to look into the future and see the variables that will exist for us ten years from when we start using gear. There is a real lack of scientific studies regarding long term steroid users recovering testicular function. There is obviously evidence that some people get shut the fuck down, but very little regarding the people who quit after 10 years and then 6 months later they are back in production, because those guys didnt need to go to the doctor.