I use the same strings and set ups on all my Les Pauls.
My Amber has always had a greatly noticeable stiffer action though. On playing and making bends, it takes twice the effort on it than my other 4 LP's. I've never figured it out. After playing any ofmy LP's and going to the Amber it feels like I go from 10 gauge strings to 12's or 13's acoustics, not the diameter, but just the force it takes to play it and make bends.
I have no clue what makes it that way. It's set up identical to all the others, has the same neck profile, etc., etc.