I've been on for finasteride 1.5 years. Not an extremely long time, but I believe my prostate has been subjected to lack of DHT enough to reach its permanent size while continuing to use the medication.
I feel no difference whatsoever. Orgasms are just as 'powerful' and enjoyable than ever.. In fact the last year I’ve been having some of the most pleasurable sex of my life, so it certainly hasn't affected anything there.
Just as another observation: I suffer from a condition called Proctalgia Fugax (stupid name, I know) which is severe episodic cramping of the muscles in the anus surrounding the prostate. Sounds a little funny, but it can be absolutely excruciating and always follows directly after an orgasm. It lasts for hours and relief usually only comes from sitting on a small hard object like a golf ball. Again, laugh yourselves up but when you are having these attacks you will do whatever it takes to make it go away, including shoving things up your *** to try to keep the muscles from cramping further. I used to have these attacks in clusters a couple months out of the year, where I could have a few episodes a week depending on how often I orgasmed. I have suffered from this pretty much ever since I hit puberty. Yeah, it’s pretty embarrassing to take some chick home with you, sleep with her, then end up in the bathroom sobbing with your finger up your *** for 3 hours.
Anyway, literally ever since the day I started Finasteride I have not had a single attack. It may possibly be due to the atrophy of the prostate and surrounding tissues or entirely coincidental, but I have a feeling Finasteride helps pretty significantly with this condition. For me, if Finasteride can treat this condition (which it appears it does) I am happy taking the drug just for this purpose.