Curious if any racers use them and is so which ones.
using race boots for all mountain skiing can be cold. does the intuition liner improve warmth for 10 degree F temps, or is a boot heater much warmer? can anyone compare the original liner with the intuition in a raceboot, Lange or Doberman?
Absolutely I use them, and I can't recommend them highly enough for race boots. I have them in both my 'off the shelf' race boots as well as my Lange world cup plug boots. They give me a far better, more precise fit than the stock liners, are extremely comfortable, and my feet never get cold anymore (I can easily ski for a couple of hours in -20 temps and not freeze my feet). You can't lose with them.
If you want a lower volume liner, go with the overlap liner they designed for plug boots. I got one of their earlier prototypes years ago (9mm high density foam vs. 12mm lower density) and still use them in my regular race boots, and I have their latest plug version in my WC boots (same thickness and density). The thicker foam in their regular liners will be warmer, but it's a bit softer and might be a bit of a tight fit in a close fitting race boot.