I went ahead and bought two sets of these.
Here’s my take: when fitting these into a shoe, you really have to work to position them correctly into the shoe. The arch can get skewiff and throw off the entire shoe. At one point, until I fiddled with them, I felt that they had a different guy’s foot imprint. One I got them in correctly, they were fine.
Fitting them into the shoe: it is best to trace around your foot as well as you can, as the thin neoprene can easily get rumpled when just trying to trace your old insole.
Though they are in general much thinner than your typical insole, I still found that my hard-to-fit right foot can feel cramped in the toe box of my shoe. This option is better than many on the market because it is much thinner than your typical insole. With other insoles, my right foot ALWAYS got cramped, and I would have to discard the insole. This was much better in that respect, and I ended up working out the cramped-in feeling after positioning the insole correctly.
Materials: Though the neoprene is nice for cushion, I feel that a Coolmax or other sinmilar material could have been glued onto the neoprene. I feel that you really need socks with these insoles. If I were to reorder, I would enquire and offer to pay good money for this addition. The carbon is not very pretty, but looks well built.
Overall impression: I only got to spin for a little over 1/2 hour on the trainer, but what I had noticed was that my feet felt quite a bit better. I could get into a taller gear faster on my trainer, as my foot was nearly glued to the pedal. I was not focusing on my feet, and my left knee felt quite a bit better. I also felt that I did not have to focus so much on my feet, as over recent years, my feet hurt a LOT on the bike.
I would not go so far as to say that custom insoles are the answer to making a stock pair of shoes feel like a pair of full-on customs, but I would say that even if you have pretty normal feet, a custom insole would be a great investment for all serious cyclists. Though it is not a custom last, it will feel closer than ever before.
Shoes are the most important part of the human-to-pedal interface. If you can’t get your shoes right, you might as well say “to hell” with that $200 fit session, as you still won’t be comfortable on your bike. If you can’t do the custom shoe route, this is a decent compromise.