My LO's poos are green on this, and when I first switched they really stank - not quite so bad after a couple of weeks.
I have used Dr Brown's bottles and found that I just needed to go to the next stage for this - I was using 1, and now using 2. I'm also using Tommee Tippee ones now as they are soooo much easier to sterilise/assemble etc (and no leaks), and I use a variflow teat on that - that has a X cut, so the harder he sucks the more he gets. I really recommend the variflow teats, but they don't do them for Dr Brown's bottles!