I generally do not write summaries and opinions on the acting and plot, that has been done by a great many others already. I focus strictly on the quality of the transfer of the Standard Def version to Blu Ray. I will say that while this is an older film focusing on govt corruption and wiretapping as well as a U.S. citizens right to privacy, the movie stays relevant and has legs. I do have the standard def version but this is not a side by side comparison.
The audio is the star in terms of disc quality. There is a big difference for any movie between lossless and lossy audio, a transparency that only lossless audio can provide. On this Blu Ray, it is lossless PCM 5.1. The audio's levels are nicely set, and if you have a decent surround system, this movie would be considered Demo worthy for showing off your home theater's audio capabilities. There is much use of all the front and rear surrounds with a goodly amount of panning between the front and rear stages as well as the discreet channeling of foley fx to both the front and rear surrounds. Your LFE channel does come into play but not overly. The audio of the standard def version also had excellent surround usage and, thus, I give credit to the original audio editors and mixers.
The video transfer of this softly focused and color muted film presents very good contrast, a touch better than the Standard Def version but I do not believe that it is because of remastering. The bit rate is certainly higher but not a whole lot; it generally averaged between the mid teens and the mid twenties and that higher bit rate accounts for the somewhat better video. There was minimal film grain, no artifacting or imaging issues. Never the less, I do not believe that you will see a night and day difference between the video of the Standard Def and BluRay versions. If you do not already have the film, certainly go for it on Blu Ray but if you do have the Standard Def version, don't expect a whole lot of difference.
The extras consisted of some deleted scenes however there was no 'play all' button so each time a deleted scene was done, you had to go back to the menu, bring up the 'extras', go to the 'Deleted Scenes', find the next scene and select. What a pain in the butt! No commentary but there was a short 'making of' of the climatic gunfight.
Hopefully, this review has been of some help to you in determining your purchase, hope I am on the correct path with a review of the transfer quality as opposed to providing plot summaries.