Hi there,
Your baby is actually doing what's normal for his age. I agree with the other mommies in that try to up his calorie intake during the day. For me personally, I never did the dreamfeed, my spirited boy thought it was party time at 10:30pm!! I did cluster feed him though until the day I weaned him at 9 months. I would give him a snack at 4, a full BF at 6 and then another full BF at 8 and off to bed. Just make sure your ds isn't waking out of habit.
As for why some babies sleep and other don't. Sure age, weight and calories have a lot to do with it, but they also sleep through when they developmentally ready. And the formula vs bm solution. All I can say is BLAAAAAAAAAAAAA. What a bunch of hooey. I always use this example. My angel niece was formula fed and didn't sleep through the night until she was 4 months old. Spirited ds was exclusively BF and slept through the night at 2 months. So I had a spirited baby who was breastfed sleep through first.......I had all the odds against me though. Just goes to show that every baby has their own "norm". Don't let anyone tell you otherwise. And if people try to talk you into something you don't want (like the dentists assitant) then just kindly say " I'm sorry, I don't remember asking for your opinion" it's a nice and polite way to tell them to fly a kite!
Maybe try 3.75 hour EASY and see how it goes. Also try to see if he's going through a growth spurt or teething. Sometimes things like that creep in when we are making the 3-4 hour transition and we don't catch it.
Let me know how you get on
- Beca