Hi OP, I don't know if this with help but... I own both formats. I've seen movies on both formats that are stunning! For example, I watched Apocalypto on my PS3 the other night - very impressive indeed, though, to be honest, no better than many of the HD-DVDs I've watched. I really don't think there is a 'clear' difference between HD-DVD and Blu Ray - both formats put out a superb picture and great sound. To be honest though I've not really warmed as much to Blu Ray as much as I have to HD-DVD, and one of the reasons I suppose is that the interactivity of HD-DVD has been there from the start. From the very beginning I've had menus that pop out with a swish while the film is still running but with the exception of The Day After Tomorrow every BD disc I have had has clunky menus reminiscent of DVD. BD is getting there, but right now HD-DVD still feels to me like a more complete product.
There was a point where I worried about the longevity of HD-DVD and was glad I had a PS3 in hand. But with Paramount's switch, Walmart clearly promoting HD-DVD, this particular sale on A2s, Warner looking carefully at Q4 hardware sales etc., I am now a little worried for my PS3. At $99 the A2 really is a no-brainer, blu leaning or not.