Ugh, I've been considering Tieks for months and have just never pulled the trigger. I probably won't until fall. And while I'd love, love, LOVE the Arabian nights, I will probably get the matte black. Everything I've read about them is positive. They are expensive for ballet flats, and I have the same issue as Una ("outlining wide feet" is a great way to describe it), but I still want to try them.
Una, if you get a pair, please post pics of you wearing them. It is likely that the way they fit you will be similar to the way they would fit me. If they don't work for you, I can probably bury my Tieks dreams.