I got the 2mm and 3mm, but the 2mm worked so well, I've hardly used the 3mm. (Note that I'm using the 2mm in boots where I have just a slight amount of heel lift w/o them.) The foam is fairly dense...

Yes, I've used them primarily for touring. I don't notice the seams, but maybe the top-front edge of the bootie just a bit, but really not until after I've taken off the boots at the end of the tour.

If you have minor to moderate heel lift, try these ankle booties from EzeeFit. They've worked well for me.

https://www.ezeefitsports.com/Ankle-Heel-Protection-s/1871.htm