I'm afraid no one can answer that question with real authority because finasteride doesn't seem to produce the same visual results for everyone. But I have observed and concluded:
It halts/slows down the progress of male pattern baldness for most people.
A lot of people experience regrowth in some quantity.
A lot of people experience mild side effects (usually temporary).
Very few people people suffer permanent side effects.
A lot of these are self-diagnosis which are really not reliable.
For example, some people might exclaim: "In one year, finasteride ruined my hair!". But how do they know that, without finasteride, it would be a LOT worse?
Chances are, you'll be ok.
Just remember that people who have negative experiences are the most vocal. So it's very likely that even this fine forum is disproportionately representing the experience of the average finasteride user.
In the end, you should read as much as you can and make your own mind up. That's what I did and I chose to get on finasteride. Everything is great so far