Does anyone have any benchmarks for these machines? Also, am I correct in presuming that the more expensive of the three have 'extra' video cards? What's going on here? Any ideas helpful since I'm about to buy. I would be using this machine primarily for travel photography (aperture, NX, photoshop etc), however also for sound engineering (as a hobby). I'm be going for the anti-glare I'm sure, but beyond this I'm a bit lost, I'm not interested in using it for anything else. I can spend that extra money on some new glass =)