okay i wanna know if this is a good guitar for metal (metallica type stuff, pantera etc.) or if i should upgrade ne thing else first...

my gear: Alden AG-20 (10 watt practice amp)
GNX3 (kick ass!!!)
Eastwood les paul knock off but w/ single coil pups

jsut curious if i'd like the esp EX-400 and wondering how it plays

the EX-400 is awesome, but you wont sound good or metal without a good amp. which you dont have.
a good metal amp will make your crappy knockoff sound metal. a great metal guitar through a toy amp will sound like you took a very expensive crap.