The G-400's are good guitars. The better guitars are usually hand assembled by highly trained people and use a higher grade of wood. So technically the fit, finish and setup of the guitar should be better. They also usually have better electronics. My son has a G-400 goth sg and it has nice action and the pickups sound pretty good. You can upgrade the electronics if you want. I'm sure some the folks on this site can give you suggestions. Also search the forum I'm sure this has been covered before.

Keep on strummin.