I was disappointed with these bottles. Unfortunately they didn't help with my little ones wind and i found them fiddly to wash up etc. Also the little rubber bits at the ends of the inner tubes aren't very robust and most of them tore within a few weeks of use. They also seem to leak and i can't stop them from doing so.
I have purchased Avent bottles and these are much easier to wash up etc and my little one gets on better with them, although they haven't reduced her wind much.
I've also tried Dr Browns bottles and found that they were the best quality very sturdy etc but you have to mix formula in a very specific way and can't shake them as they leak everywhere. They didn't do much to reduce wind either so i have reverted back to the avent bottles. These are the simplest to keep clean and my baby drinks well from them.
I have heard good things about all these brands so i thought it was worth trying all the different ones available to find the best for my little one.