I also usually find that shoes with back zipper could be quite uncomfortable as well. Maybe it's just me, but the zipper always digs into the back of my ankles! Well, these are seriously the perfect fit - there's no rubbing or digging whatsoever.
I do think these run on the small side - I am finding that nowadays I am a size 6 for the most part (sometimes even 5.5!) but these are size 6.5 and I can't imagine them being any smaller.
These heels are supposed to be 4 inches high, but they really don't feel that high to me at all.
I also really like the somewhat uneven color tone of the leather - it gives them a softer and more natural look. I almost always prefer the look of used leather to brand new leather.
This style really works with everything- they look cute with skirts, shorts, pants, dresses, etc. They can be dressed up or down, for work or for casual wear, and with pretty much any color. I'm seriously considering getting another pair of these! They come in a "blue gray" color which might be interesting!