I will admit to having a couple of pairs of extreme-type shoes, which I bought because I wanted to see if I could actually walk in them. The answer is no, and the problem is two-fold: 1) They are made so cheaply that they're not even nice to put on, much less walk in, and 2) I do not enjoy the experience like I thought I would. Even though no one has ever seen me in these shoes, I walk so badly and awkwardly that I feel silly. If I make myself practice, I do get a little bit better after a short time of warmup, but on the whole I do not like wearing them. And yet still I aspire to wear them. I cannot explain this paradox.
I will say one thing for practicing in 13+ cm heels. After wearing them for 15 minutes, your 11-12 cm heels feel like butter! I wish I had some evidence to actually prove it, but I feel like I walk so much better in normal height high heels after spending a quarter of an hour in extreme heels.