Q1: How do you gel with the Epi? Could you part with it? Is the guitar "right" for you?
Q2: Can you try the strat?
Q3: if no to Q2, have you played a strat?
As other have stated, they are on par in trade, but if you haven't considered the above questions, I think you are missing parts of the puzzle. I have some low-end guitars that are right for me that I would not part with. I've had high end guitars that just didn't pan out.
I've owned Les Pauls, wanted one, and remember going to a store to walk away with one, although I was always intrigued by an SG. Tried an SG for the first time and within 5 minutes knew that guitar was for me (sorry LP).
Lots of things to think about!