Does anyone have a strong opinion on whether it is worth spending the extra money on a 10,000 rpm system drive for a Core 2 Quad machine that will be used for some HDV footage editing in Premiere Pro CS 3 and heavily used for encoding those hi-def video clips with Sorenson and Cleaner XL to WMV, QT, Real, Flash, etc. Of course the video files themselves will be on seperate external hard drives, and I have always used firewire with great success.

Just wanted to know if the system drive speed would make a bit of difference strictly for the encoding performance.

By system drive you mean the drive that contains your applications, OSX operating system, etc. - right? 7200 rpm will work just fine. I prefer to have a second internal drive for storing graphics files, final QT movies, etc. that I need often or want to reuse - use the money there.

I agree with the above. The 10,000 rpm drives are optimized for datacenters with lots of random read activity as it gives lower latency. Video is streamed and our modern motherboards and OSs do whatever prefetches to fill the pipeline.

10K drives can be expected to run hotter, make more noise and possibly have a shorter lifetime.