I have a pair and they are certainly comfortable. I bought them for a wedding because I liked the idea of folding the shoes and putting them in my bag for later in the evening.
That said, they are comfortable but not the *most* comfy pairs of shoes I've worn. (My Nike Free 5.0 Flyknits (Wide!!) are the best, hands down.)
And, they are expensive for a ballet flat, as you say.
I have other ballet flats that are almost as comfortable. I bet if I added a cushiony insole, they would approach the comfort of my tieks, easily.
But it's true, the color choices are beautiful and I do love the blue soles. It really is a beautifully designed shoe. If a particular color really speaks to you, you could always try it out. It looks like they do accept returns.
Happy hunting!