My garage floor was pretty much new but I have a friend who had success with a very rough floor. My floor has held up very well for the two years I have had it. I do have some chipping on spots where I often slide my jack but that's about it.
I just saw your pictures and your garage floor looks great. I've heard mixed reviews on epoxy coatings and am hoping you can give me an honest opinion. Did your floor have any concrete problems? ... mine has some surface crumbling due to winter salt melting off the car. How long does this process take? About how much $$ for a 2-car garage? Would you do it again? Any other things to be aware of?