So... I got this Les Paul copy... and I've never tried a real one... So how am I going to find out how good my copy is? what do i have to look for?? and it's by the way NOT an epiphone...
doesn't matter.
all that matters is do you like its sound? what sounds can you get from it? how does it feel/play?
don't worry about the status of wether it's like a paul or not, and besides, if you say you have never played a paul how are you sure it's the guitar you want?
You need to just go out and try some. To tell you the truth a lot of copys or knock offs are pretty good the only major difference is where they are made and pick ups. If your happy with the way your plays and sounds don't worry too much about it.

I'm also thinking about the sustain, and how easy it is to do pinch harm. on it...