Absolutely everything in or on the guitar is lower-spec than a USA Gibson. Fact. Wood, hardware, lacquer, electrics...everything. The Korean/Chinese/Indonesian Epis are effectively authorised lower-cost copies of Gibsons, designed to look the same, but they're not built the same. You have a Korean Samick build there, and I rate those as usually very good build quality. I've owned 3.
You've also upgraded key components to Gibson-level spec. Through a good amp, yours will sound undistinguishable from a "real" USA Gibson, at a fraction of the price. If I were you I'd try a few USA Gibsons and compare the feel and the finish. Don't expect them to sound better. Only you know if they are worth the difference in price. If I were you, I'd hang on to the Epi and spend my money on something else - a different type of guitar, or a really good amp.