[citation][nom]amien[/nom]Thanks very much for that info, I'll be using Premiere Pro cs5, so i'm not sure if that supports Quick Sync? Out of interest, what card was used (if any) in the cpu benchmarks at[/citation]
Premiere pro CS5 does not support quick sync. There may be some performance boost it can take advantage of, but they will need to re-write their exporter for full support. However, CS5 suite has excellent support for CUDA (nVidia) cards, which makes it a moot point as it will use CUDA for software encoding/editing instead of the CPU anyways.
Also note that the presence of a GPU will by default disable the on-board video anyways. So the review of this process is mostly for the benefit of laptop users who do not have nice add-in cards and need to take overhead off of their CPU.
Lastly, Premiere Pro is a great editor, but not an encoder or cleaner. I am 2 gen behind you on software, but even with my friend's CS5 premiere the export (when transcoding) is relatively slow, and not best quality even with the best codecs. You should export to whatever format you are editing in, and then use a script based program such as AVS/AVSp combined with Virtural Dub for your final compression to AVI, or just use quiktime Pro for .mov or h.264 compression. AVS will give you extreme amounts of control over your file size, quality, and post-production cleanup, as well as give you faster export times for most compressors (obviously this depends greatly on how much cleanup you do, as a lot of cleanup in post will take time).
Obviously, never edit in a compressed format as the lack of key-frames can mess with your cues and transitions. You can use fully key-frameable compressors (such as h.264 which can be fully key-framed, lagarith, or others) which will save some space, but will give excellent quality without degradation on editing. This will also allow a near instant export because only transitions need to be rendered, then use AVS for your final encoding/transcoding. Again, not the simplest software to use, but it can give that nice pro result without the cost of a pro exporter.