I've had both, and they're both great. Jackson uses a thinner finish, which makes the guitars more resonant and feel better to play, IMO. But prices on both are pretty outrageous these days.
I had a pro series king V for $1k that was punching harder than some of my Japanese ESPs from the early 2000s.
I don't have any of these guitars anymore. ESP finishes are so thick they deaden the guitars, a lot like how my Kiesels were about 10 years ago. I'm down to 4 custom guitars, and it seems like where I want to be. I don't think I will be buying ESP or Jackson again moving forward because the prices for what you get don't sound and resonate as good as my Hapas guitars or my Bauers.