Some moms do a little cereal in the bottle to thicken it up. With the AR, you might not need that. I also find that mixing it first in another container helps.
2 of my daughters were spitters. One was projectile vomiting. The first was so many years ago they didn't know anything about acid reflux to speak of and had mentioned surgery if she didn't gain wait. She still gained weight and it took at least a year for her to grow out of it.
The last daughter came a long at a time when there was at least many choices with formula. I tried everything on the market and I did not wait for doctors approval. Maybe that is one good thing about being an older mom. I realize that the doctors don't know everything and I can't afford to pay a co-pay every time I want to try something.
With my youngest I had to stop formula all together by the time she was 6 months old. Fortunately by then, I had her on a lot of foods. We finally settled on vitamite which is a soy drink. She's happy and healthy today and if she is soy intolerant, it's not unmanageable. She still gets diarrhea easy. But she doesn't feel too sick with it and we don't really see it only with milk.
Suzi