The epoxy goes on as thick as paint. When you've acid washed the concrete, it will feel like sandpaper, and when you put on the epoxy, it will smooth that sandpaper textured surface out. If you've patched a hole in the concrete, you'll be able to see where the hole was. If you put the paint flecks on fairly thick, it hides a lot of the imperfections though. You can still find them if you look for them, but they don't stick out like a sore thumb. I'd give the UCoatIt people a call and see what they say.
Will
Will