My 5 month old has had acid reflux diagnosed since she was 2 months old. She wasn't sleeping more than 40 minutes at a time - which meant I wasn't sleeping at all! She would only sleep if I was holding her sitting up. We tried the bouncy chair, swing and the carseat but none of them would let her snooze! Luckily, I stumbled across the Nap Nanny!
The Nap Nanny is a big foam wedge that is also raised at the feet so the baby doesn't slide down. We had tried every sleep positioner on the market, but little one kept sliding off of them. I would find her at the bottom with her face in the bolster (thank god most of them are mesh these days!)
The first time I put her in it she slept for 3 hours. I think she was making up for all the lost sleep! At 129.99 it's a little pricey, but sleep is pretty valuable these days!