I have had some of these bottles, for my girl, since they came out, and I have to say that I would not use anything else.  I am surprised by "IAMCM's" comment below.  They are very easy to clean, and I have never had a problem... and I LOVE the designs,  they are so much easier for my girl to hold then other bottles I have tried along the way.  My girl is walking around now, and she has dropped the bottle a couple of times... the designs have not come off....and they do not break!!!
Anyways, I get a couple of these bottles for my friends who are pregnant now, and they were thrilled with the gift.