Been taking propecia for 5 years now and I wish I had started taking it earlier. My hairline is exactly the same as it was as when I started, and it had been receding at a slow but steady pace before using it. Much easier than taking minoxidil--just pop a pill at night, no messy, smelly lotions.
Sex drive went down maybe 10-20%, but that might have been from getting older, hard to tell. In any case, it's somewhat of a relief to not think about sex all the time.
Other things I've noticed: it seems to slow the formation of fine lines in the face. I've heard other users talk about this as well, maybe something to do with DHT and collagen.