I had good experience. Some bruising first day but no probs in 11 months with feeding/nipple pain. So it's not helpful when people say to quote one post: "one has to endure sort of 3 weeks of (some) pain"
Not everyone does. Be realistic, you might, but you should definitely seek good advice if you do.
Advice in UK (I'm English but had DS in US) seems to be very patchy and contradictory. And we've all become obsessed with fashionable books / NCT peer pressure instead of using our own iniative as mothers.
DS used to lose concentration so instead of 'feeding for 20 minutes on each side until breast is empty (like there's a gauge!) as per most current advice, I used to switch from one to the other and back. I later found this 'method' in a 1970s book someone lent me. I guess my point is really that it can help to relax, and listen to your own maternal instinct, in addition to getting well informed.
I fed on demand (and no, cluster feeding isn't constant feeding, it's feeding more often at certain times mostly evening), but I was also strongly advised to look for the difference between proper feeding (listen for the swallow and little exhalation), and comfort sucking. And try to limit the latter. If baby is just messing for 40 mins you are more likely to get sore. If you are hung up on giving exactly x amount of time, you might find yourself getting chewed more than you really need!
I was told they need about 5 mins only in the first few days at least, yet have seen friends struggling to feed newborns for the regulation 20 mins a side and wondering why they're getting so sore and baby not feeding, getting totally discouraged.
Sorry, long post, but I get upset seeing people stressing needlessly because of bad advice / peer pressure. I accept there was an element of luck for me, and people do have real medical reasons for having a hard time. I'm hoping DC2 due soon will be as easy but appreciate she could be completely different, as was the pregnancy!