I dont' know if my experience is unusual, but I've never had any problems with root canals. The problem has always been what lead to the need for the procedure, e.g., an infected tooth.
I always wonder what people did before dentists (or modern dentistry). I mean, an infection kind of takes over everything (that's been my experience anyway). On the other hand, I've heard of people who apparently let their teeth go untreated until they fall out.
That reminds me: I was in a certain state awhile back (somewhere south of Iowa), went into a gas station/convenience store, and the woman behind the counter pretty much didn't have any teeth. And she was fairly young. Then a guy steps up beside me as I was paying, and he made a joke to her about it--cause he didn't have any teeth either.