I have them in XL and on Meindl Dovre boots size 11. Wicked combo but a bastard to put on I put them in boiling/warm water first to loosen them up, once I get them on I put them on the radiator to dry them onto the boot.
Just come back from a week in Scotland wearing them everyday 10+ hours on the hill (12+ miles a day all up hill!). Came off once as I got caught on a branch and I was walking heather banks and clear fell. outstanding combo IMHO.