I think the latch is ok - I've been paying attention to it, after having a horrible experience with DS1 where he wasn't latching properly for weeks, I got very sore, I used nipple shields - badly, as a result of poor bf advice - it didn't improve, he still didn't gain weight, it was all horrific...
DS2 was weighed today, and having lost 8% of his birthweight at 3 days, he's now regained 2oz in the last two days, which seems like an ok gain and hopefully indicates he's getting enough food? All the other signs seem right too - he's feeding every 2-4 hours, he settles easily at the breast and comes off looking satisfied, he settles for long sleeps in between feeds, he's clearly drinking (lots of jaw movement, and you can hear loads of swallowing), he's filling endless nappies. The nipple comes out of his mouth well-shaped (not the dreaded lipstick-end I used to see with DS1) and I'm not generally too sore - just a little tender, but then it's only five days in.
Oh (so as not to drip-feed), the hospital midwife said DS2 has a very small tongue tie, so we should keep an eye on it and get it treated if it causes feeding problems. As I say, we seem ok so far...
...but I will certainly keep an eye on things. I've just realised in the course of typing all this out that I'm really quite anxious to make sure things go better than they did with DS1.
(If anyone is interested and/or is having similar problems - there was a happy ending! We persisted, sorted the latch out, he promptly shot up to the 91st centile and has remained there ever since. He was EBF for 7.5 months in the end, before I chose to stop).