#3
The only differences are the look, the neck (Ebony on the ATX, rosewood on the Hellraiser) and inlay (12th fret only in the ATX), and the pickups (Blackouts in the ATX, EMGs in the Hellraiser).

Keep in mind that the Hellraiser has coil taps, the ATX does not. Although i have heard blackouts are better than EMGs. Just what i've heard, though.
#4
blackjack for me...ebony and blackouts are two great things to have on a guitar
ESP Eclipse with blackouts (Snow White)
Taylor 814ce (tabacco sunburst)
Dean Dime o Flage
Spider valve mkii
Fender Super Reverb
Peavey Vypyr 15
#8
Id go for the hellraiser actually.
Gear:

Guitars:
PRS SE Fredrik Åkesson
Schecter C-1 Custom FR
Schecter C-1 Plus
Schecter Damien Elite 7
Epiphone Les Paul Ultra II
Fender acoustic

Bass: Harley Benton HBB400TBK

Amp: Peavy valveking 112
Line6 POD HD500