I had a Peanut Shell with DS1 which was great while he was small but it put too much strain on one shoulder when he got heavier. I also used a Baby Bjorn which was ok but I didn't have the one with lumbar support.

This time around I have an Ergo Carrier and it is fantastic. In fact, my DS2 is asleep in it right now. He has reflux but he'll sleep great in the Ergo. I would 100% recommend it to anyone. I've only had it for about 6 weeks but it's already worth it! He can be in it for a couple of hours and I still don't get a sore back (he's about 6.5kg at the moment).