CDDA < FLAC
In short, if your source is 96khz or higher, try something like FLAC. If it is CDDA, your wasting space with FLAC. That opinion is not from someone who is a technical expert on sound, but from someone who has remastered 100's of songs.
FLAC is severe overkill when your input is CDDA. There is a much more significant visual difference between BetaMax and VHS than the audible difference between FLAC and MP3@256 if your source is CDDA (mp3@320 and you're sort of wasting space again). So, how much visual difference is between Beta and VHS again?
In 2003 I started remastering individual songs that had never been remastered using a plethora of DSP software (no big boy hardware :-( ). If I couldn't find a studio master (which were far easier to find then), I would choose CDDA. At some point, I came across a master of Moon Safari by Air (not for remastering, but because I liked it). The master of course didn't sound the same as the CD I had, so I looked for my CD for comparisons, but I couldn't find it. In desperation to find the differences by comparing the master to my CD, I substituted .mp3 files for my CD as the source.
A week passed and the differences became apparent, however I still wasn't using CDDA, so I acquired the CD version to ultimately compare CDDA to .mp3. What I found between my 256.mp3's and CDDA was eye opening. Not only was 99.5% of the audible information there, but more importantly, the information that was NOT in the CDDA but in the master, was also not present identically in the 256.mp3's, and the .mp3's were sourced from CDDA! If CDDA didn't have it, .mp3 didn't have it identically.
You really can't remaster from CDDA, but whatever you can make better out of a CDDA, you could do just the same from decompressing a 256.mp3. I lived it.