I bought an Ibanez GRX20 for $150 and Im liking it so far (even though i've been playing through the crummy mic port on my PC). But I need an amp now and I've decided it is definitely going to be a Cube. However, I am wondering if I should go with the 20x or 30x. The 30x is $230 and has more features. My goal is to produce the most metal sounding tone possible out of my guitar. So, what would you do?

(btw, please don't recommend the microcube. I realize its potential but I don't want it, too small. Also please don't recommend anything besides roland cubes...I'm set on a cube) Thanks in advance.
The 30x is great, I have one, defiantly one of the best 30 watt solid state amps for metal you can get. Get the 30x, more features then the 20x and I use all of them.
Schecter C-1 Hellraiser
Peavey 5150
Vader Cabinet 4x12
Roland Cube 30X
Line 6 Toneport UX1
Morley Bad Horsie II