Thinning Sucks --
You say you've maintained but now you're experiencing a thinning crown and frontal loss? Which one is it? Based on the 5-year Propecia results, most people (90%) maintained or improved hair density from baseline after 5 years on finasteride. That includes the front.
As for me, badasshairday, it's a coin flip. I've been on finasteride for so long, I can't really remember sex before it but I can say it's not the same anymore. Similarly, I don't know if some other things are attributable to finasteride (weight gain, etc.) or not since I can't really remember my pre-finasteride days. I bet a lot this happened to a lot of people who continued using finasteride after the first couple of years -- they "forgot" about their side effects. It all tends to blend together after a while.
My hair: No one knows I'm taking finasteride and I don't think anyone thinks that I'm thinning. I, myself, don't even know anymore. Some days I think my front is thinning but I can't remember how it was when I first started treatment. Again, the blurring of things. Sort of a catch-22. I have a couple of options: 1. Go off finasteride and both the side effects and positive hair effects would be made clear; or 2. Stay the course. At this point, I'm gonna pick the latter.
D.