always read user reviews on a Blu-Ray disc your interested in buying. for example, i too wanted to purchase Heat on Blu-Ray. however, i read several user reviews on Amazon.com that bascially said save your money because the transfer is no good. i just kept my my regular DVD and passed on the Blu-Ray.
i'm not sure what sort of televison you have, but perhaps you should look into a professional calibration. if you're always watching DVD's/Blu-Ray's, might be worth looking into. having your tele calibrated can be a night & day difference as far as picture quality.