I have learned that just because a shoe is flat, it does NOT mean its comfortable! A few of the things that really count in cute flats are breath-ability, stretchability, and padding. I know this isn't very PC, but I totally think its worth it in a shoe to get leather. (sorry cows!) If you have pleather, you probably won't get any breath-ability or stretchability.
I had a gold pair that I REALLY wanted to like, that I bought to take the bar exam (in Virginia, you have to wear business attire while you take the test...and I didn't want to wear heels), but they got really scuffed up. So I went over the scuffs with a gold paint pen, but it turned out being the wrong color gold...anyway, they have been sitting in my closet for a few years now. So I decided to chuck them and replace them with....
These beautiful new metallic, breathable cutout flats from Dolce Vita! I am really liking them and they go with absolutely everything. They also feel like sandals because of the cutouts but have a little bit of a dressier or more proper feel because of the closed toe and heel.
Stay tuned for more upgrades...from plain black pvc ballet flats and brown tweed that hurt my feet to the new, more fun and young versions! Did I really mention my new, younger and less formal work environment? :-D