What type of music do you want to play?
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Quote by utsapp89
^I'd let a pro look at it. Once you get into the technicalities of screws...well, it's just a place you don't want to be, friend.
i play lots but i want this guitar to be a more metal, rockish kinda guitar
Ibanez SA160QM
Laney HCM10
Squier Bullet Strat
MXR Carbon Copy
Zoom Tri Metal
Modtone Flanger(mini)
Korg Pitchblack
Timtone acoustic
It really depends on what you want

the Rg: 24 frets
Edge Pro trem(Great)
Prestige Neck
Basswood Body( Brighter than Mahogony, not as bright as Alder. About in the middle
Prestige- Made in Japan
Comes with Case
Arguably Not the best pups

The S: 22 Frets
ZR trem(Great)
Wizard 2 Neck
Mahogony Body- Darker sounding than basswood
Not Prestige- Made in Korea. (sometimes not the best QC)
No Case
Not very good Pups

The Rg and S have different body shapes too, the S is thinner, and the RG is thick.
The Rg would be built better.
Its really up to which one you like, both are good guitars, but if you do not need the quilt top on the s620, you could get the s320 which is the same thing but with weathered black finish. It is also 300 dollars cheaper, and you can get some nice pups for it with that 300 dollars.

But wait, NAMM is going to bring some new ibanez S series which you may like. Im waiting to NAMM (jan 17) to purchase my guitar. I am also trying to decide between an ibanez RG and S.

hope that helps a bit