My wife says the flexibility in the toe area is the best she's ever experienced, but at the same time it is not flimsy. The heel (just under 2.5") provides better balance and a more stable position and stability.
For me, I found the shoe immediately wrapped around my foot like a glove. There is not a full shank, so the front is flexible. In the past I didn't like this type of shoe (no shank), but what makes this one different is the the sole of the shoe (ex. the suede area) is a little thicker than average so I feel like I have some comfort and support, yet it is flexible, but not flimsy.
We liked them so much we've already ordered another pair each.