I posted my initial nipple shield lament here:
We kept at it. I tried at least once per day and any sign of tears, I immediately put the NS back on. He slowly took to it more and more. Although, I have to say, we would often take two steps forward and one back as he didn't immediately stop altogether. The first day he took from bare breast more often than not was Mother's Day (but there were regressions here and there since then). Best gift ever! I was lucky as his latch was very good and I experienced minimal pain/soreness. I was worried about latch because I thought he was too used to keeping his mouth smaller around the NS. Another thing to note was that meals are now much shorter in duration. The NS takes longer to drink from, I guess. This sometimes concerned me but he's gaining weight just fine. We went from 45-60 min meals to 5-15 mins! There was a transition time when he was frustrated with both the NS and without. He didn't know WHAT he wanted, but once we got past that and were able to do night feedings (which ultimately became the easiest feedings for him to deal with) we were over the hump. I now confidently leave the house without the NS and he feeds like a pro. I really believe it's developmental for some babies.
He's now 4 1/2 months and has been fully weaned from NS for several weeks.