I've only been in the world of Blu for a week and a half now. I have been lurking on this site and the avs forums for a while. Reading comments on film and quality and all, I really wasn't dissapointed when I got my ps3 to play blu-ray films and upconvert my current DVD collection.
One thing though as striken me is that, besides a few exceptions, is the lack of extended cuts and director's cuts on blu-ray titles while standard DVD versions have been available for a long time. I understand studios want to milk a title (cough Evil Dead folks cough) but some title were recently released as extended cuts and are nowhere to be seen on blu-ray.
A personal favorite of mine is classic action Swarzenegger "Commando" annonced for blu-ray. Cool, I recently got rid of my old early Fox release version to get the extended, anamorphic cut. I was about to pick it up until I heard about the BR version being released soon. BUT, it's not the extended cut hence I'm likely to get the standard DVD version until the BR version comes along. That said, looking at reviews of older flicks some aren't worth the investment because the upconversion is pretty much the same as it's BR counter part. I've recently watched "The Ten Commandments" upconverted and frankly I doubt it will be better in BR. The image is amazing at it is for an over 50 years old film.
I've always functionned like this when getting a title I already had. This was on standard DVD so some don't apply but I think you will get the idea.
1. Is it an extended or dir.cut?
2. Is the image quality been remastered (for classic films)
3. Is is anamorphic (commando and early Fox, Paramount and Buena Vista titles weren't when it was first released)?
4. Do I like the film to the point of changing versions for extra documentaries or features?
Besides #3 this is how I'm going to work with getting BR discs. This site is a great source for disc reviews

. Hence, studios better start bringing in some better cuts of their films if they wan't this guy's cash hehe.