Dig a little more on the axe. I play pretty much only metal, mostly death/melo-death type stuff, and I find it pretty easy to get amazing metal tones out of the axe. Way easier than any plugin I've used, and I've used a lot of them.
Why not post up a preset you've been having trouble with? Some of us can take a look and see if there's anything we can point out.
What are you listening on? Personally I use a 2x12 with a matrix power amp, but I can also get great tones out of my studio monitors or XiTone wedge. Your setup here will make a big difference in how you might want to tweak the preset and also how easily you'll get the tone you want. In my experience, a lot of what makes a great metal tone comes from the feel, meaning a cab at decent volume. It's way harder (not at all impossible) to get a great metal tone through studio monitors or headphones than it is to get an awesome sparkly clean, again this is in my experience.
Tell us a little more about what you've been doing and we might be able to help you out. I promise you once you figure it out you'll never want to touch a plug-in again.
What are some bands that might be an example of the tone you're after?