Obviously everything is subjective & down to opinion,I drew my conclusion when I sanded down my epi (custom shop fwiw) to refinish it & discovered a 3 piece neck opposed to a Gibson's 1 piece, the back consisted of at least 3 pieces (mahogany I'm guessing but could be alder) & a veneered cap made up of how many pieces of who knows what? & the finish was applied thickly & poorly. Maybe the older Koreans are comparable to quality to japanese guitars, I wouldn't doubt it however modern epi's just aren't
I'm not saying epi's are poor guitars by any stretch for the money they're superb, but as bare bones guitars (Neck/body/fretwork etc) they're not even close to a Gibson.
If you load an epi with top of the line hardware will it outperform a studio? I'd say possibly to quite likely, but if you put the same hardware into a studio IMO that would be the superior guitar.
Don't get me wrong I'll be dropping some quality pups, nut & tuners on my epi when it's resprayed but I'm very pessimistic it'll retire my gibson.