Alright so right now i have the chance to buy either a new Ampeg SVT410HE or a used Aguilar GS212. I play mostly metal and stuff like that. What would you guys think?
There's no such thing as a cab for a particular genre in the bass world. Most tones can fit most genres. It depends on what you plan to get out of it, and what sort of sound you want.

Personally I'd take the Aguilar over the Ampeg any day of the week.
It depends on what the rest of your band is using, how large your venues are, and how much wattage the two cabinets can each take. If you play loud and fill decent-sized clubs, you'd probably be better off with the 4x10.
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The frequency response of the Aguilar is much better than the Ampeg. They have a similar SPL, but I'd go for the Aguilar as I really dislike the tonal colour of Ampeg cabs.
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