I was hesitant to purchase these because some reviewers complained of miss-matched sizes but I am thrilled that my bravery overcame!  Lucky enough to snag these in a lightening deal a few days ago,  they arrived today and I am here to report that they have exceeded my expectations!  I took them all off of the velour coated cardboard which they are attached to,  and examined the posts.  They seem to be well made and all three pairs are uniform in size, yet each color are slightly different shapes and sizes from differing colors.  With my set,  the pink set are the largest and a little more perfectly round.  The Peacock are a little more flat but a tad wider than the pink,  and the white ones are not quite as round as the pink ones and a bit smaller in size.  They aren't "perfectly" shaped because they are cultured!  With a head separating each earring,  they will look exactly the same,  in my opinion!  :)
My favorite is the Peacock.  Holding them in natural light they are purple-ish blue and really stunning.  I couldn't be more thrilled.
 My only complaint is that I intend to give these as a gift to a 16 year old and I wish they had come with a description so that she would know they are indeed real Cultured Pearls without me having to tell her!  The packaging is not fancy yet sufficient and sturdy.  Very minimalist.