M.H.
I have 4 kids and I personally think the new Nuk Orthodontic are the best and worked really good for switching my 8th month old at the time who had never taken the bottle. To me it seems like the shape and flexibility is the most like the actual breast and my son totally went for after I tried three other kinds of bottles incluing Dr. Brown's and Avent. I have had a few friend use the Dr. Brown's and really like it also.
M.