The problem isn't the hard panning of the guitars. Everything in the first mix sounds scooped, meaning you've pulled out all that beautiful mid range that we like in our rock music. Your other major problem are the drums, which are way too ambient. Don't get me wrong, I love a big room sound, but you need a cracking snare and punchy kik for this kind of track, and this will probably help with your "depth" issues. There is no depth to sound when you can't pinpoint any part of the sound source.
In a stereo image there are planes of space: panning—left to right; frequency—up to down; balance—front to back; reflectivity—far to near; and contrast (dynamics)—sparse to dense. (I go into this in great detail on this in my book).
There's nothing wrong with using LCR techniques when mixing (Left Center Right in which parts are hard panned). If you don't pan your guitars hard you're not using the full breadth of your stereo image, and if you think about it, that would really be no different than putting an HPF and LPF on the entire mix to reduce how much of the frequency range you use. In either instance you're reducing one of your planes of space. In this particular case, the reason people are even noticing the guitars is because you have no close source information in the middle of the mix. Part of this has to do with no real melody instrument, which would normally take up the middle, the other part of this is the lack of a pinpoint close snare and a pinpoint, hit me in the gut close kik source.
Enjoy,
Mixerman