My son would absolutely scream his head off because of colic before I purchased a set of Mam anti-colic bottles. The difference was immediate! After his first feeding with these bottles he burped well and settled into a restful sleep. More importantly, this trend has continued! It was heartbreaking watching him suffer the way he did and I'm so glad that this bottle has helped. I hadn't purchased them earlier because of complaints of different parts (now I know there's one extra step in putting this together, so complaining about screwing the bottom on as taking more time is just plain lazy), and because of complaints that the bottles leak (I've had minimal leaking, mainly when I try to put the bottom on the bottle too fast and don't pay attention to how well I've gotten it on). Even if there were more steps and the leaking was worse I'd still use this to get the results. It's worth it to not have my baby screaming in pain, and seriously not all that bad to deal with. I've ordered more.
Oh and the sterilization feature is awesome. No need to boil, just assemble it as directed and pop it in the microwave! Nifty!