Thanks for the all the feedback guys, I really appreciate it. To update, I've made sure I have the most up-to-date firmware, drivers and burning software but none of that has helped much. After testing a little more, I found that most of the lag, i.e., complete system lockup, takes place when the drive is preparing to 'scribe. During this time, the countdown to finishing ticks down but resets every 10 seconds. After about 2-3 minutes of this the drive actually begins to burn and countdown properly, the lag decreases but it's still enough to be a little annoying. I can browse the internets but I get lag spikes every 30 seconds or so, lasting less maybe 5-10 seconds. Some relevant info that: CPU usage is minimal, the burning program takes around 415 mb ram, and the hard drive appears to be entirely occupied by Lightscribe.
I think for now I'll just accept my drive's shortcoming; I don't Lightscribe very often and otherwise the drive functions flawlessly. I'll report back if I notice any fixes or improvements.