I have only used finasteride for a months ,and I have has side effects. On my second day I noticed my semen was very watery, this has continued. During the first couple weeks my libido lowered, although that was a pretty short lived side effect. During masturbation my penis sometimes feels sensitive/tingly/numb, that happens less often now.
I think people worry too much about side effects maybe to the point where they imagine side effects. I guess I'm the type that doesn't worry about being one of the few people to have serious side effects. The lowered libido thing doesn't bother me at all, I mean if you desire sex less then you don't miss it. I would be frustrated if I had sexual urges but couldn't get an erection. Honestly though I'm not sure I would stop using finasteride even if it didn't allow me to have an erection.