I recommend to the form (near the breast) and the "difficulty" of silicone to suck (which effectively avoids the ease of the bottle and keeps the smooth running of breastfeeding). As for the "anti-colic" effectiveness, I am more skeptical (it takes more than 90ml in the bottle, is therefore not appropriate in the early days), for one baby GERD were related to dairy products that I was using and not to bottles.
