I am still in love with my Zipfits (women's version) after two full seasons. No change whatsoever in the fit. Hold my heels like a vice (but not painful.) Will easily remold without reheating even in a different shell, which is one of my favorite things about them. I finally relented that my Salomon Instinct CS 90 boots were just not quite the right fit. Went to Footloose in Mammoth last week and demoed boots for two days. The Zipfits easily went from one boot to the other with no reheating...just wear them in the house for a bit to let the heat of my foot reshape them (which was minimal since they are already shaped to my foot.) Doing this gave me a very accurate feel of the boots I was demoing because it was MY liner molded to MY foot I was using.
As far as being careful putting them on--I think you just need to make sure you seat your heel immediately each time by lifting the liner with your foot in it up and down inside the shell. This gets your heel back deep into the pocket. It's really no different than if you cram your feet into a pair of shoes without making sure the heels and the tongue are not crunched down. Wear them like that and not only will they not be comfortable, they also won't last long.
I've never used Intuition liners (probably never will--I love the Zipfits that much.) But when trying the same boot on with my Zipfit liners vs. the stock liners (Tecnica Inferno Crush) there is NO comparison. I can't even imagine trying to ski in the stock liners.
Zipfits will last for many years and through several boots if you treat them well. A worthwhile investment for sure!