Not posting a question here, I just thought I'd share my experience in case it was helpful to anyone.
My DS has a high palate and my nipples were pretty flat, so he just couldn't latch. After 3 horrible days of finger-feeding with expressed colostrum a lactation consultant suggested nipple shields. They worked like magic! He latched immediately and fed really well.
My midwife advised me to try and do without as she felt it would affect my milk supply. My attempts without never worked. He became agitated, clawing at his face and screaming, so we just continued with them. They never affected my supply, baby is on the 98th centile for everything and I didn't find them a hassle. I was happy to stay on them indefinitely.
But... DS apparently had other ideas. One day at about 3 months of age he just refused to latch on the shield. He just pushed it out his mouth and became more and more upset. I took off the shield and he latched immediately. Since then he's managed to feed without shields. I've no idea what happened, why he could suddenly feed and why he took against the shields. I can only think he gets milk quicker this way or he doesn't like the plastic taste.