Wow that suprises me. I used the ordinary ones with DD1 and 2 but have used Avent... everything since DD3. I haven't really noticed any difference, Although I found them the best for coliccy babies. Tommee Tippee, I think it is, has a new flexi teat and bottle out two 150ml bottles and teats and covers for $20 in woolies. They are supposed to simulate the breast right down to the flexi teat and the shape of the bottle. I was tempted to buy a pack, but really have heaps of Avent ones at home. hmmmm makes me think.