Resurrecting an older thread... I'm looking for some insoles for my Lowa Tibet GTX boots. I've tried a couple of insoles that I have in different boots, but they either don't have any padding like the stock insole, or they are too thick and push my heel up too high causing blisters. I'm looking at the Synergy insoles and am interested, but I was just curious on the thickness of them. Are they about the same as a stock insole, maybe a little thicker? I can't have them two or three times as thick, that is for sure. Second, is the custom fit worth it? It is an extra $25 which puts these insoles at almost $80. I can spend 80 dollars a lot of ways and just want to make sure I'm going to be happy with these.