I spent the majority of the afternoon watching THE BOURNE SUPREMACY on HD-DVD. The Bourne films are being individually released on Blu-ray soon (box set already out but too expensive for me to buy), and apart from an upgrade in the soundtrack from Dolby DIgital Plus to Dolby TrueHD on the Blu-rays, there wouldn't be any difference in these discs, so I won't upgrade; I'll continue to enjoy what I already have (and paid almost nothing for: I got one of the BOURNE films on HD-DVD free and the other two were $4 close-outs).
SUPREMACY had been my least favorite of the three films, but looking at it again today, it's really a fine action film and no better or worse than the other two. They're all about equal in quality: thrills galore, fast paced action, and great cat-and-mouse plotting.