There is no difference in the data between a FLAC and WAV file. The FLAC is a lossless compression format similar to Zip files, but designed for music.
If one is hearing a difference between the two formats, there are two possible issues.
The first is that any difference is due to the extra load placed on the processor in decoding the FLAC file.
The other possibility is the difference arises from subjective perception.
The more vocal adherents of each school of thought will try to pressure you into their camp - "anyone could hear the difference" or "your system isn't good enough" or "no one can measure a difference" and so on.
The key is to not worry what others think. Experiment for yourself - it is pretty simple in this case to stream FLAC and WAV files of the same song back-to-back. Once you've decided what works best for you, run with it and ignore the naysayers.
If one is hearing a difference between the two formats, there are two possible issues.
The first is that any difference is due to the extra load placed on the processor in decoding the FLAC file.
The other possibility is the difference arises from subjective perception.
The more vocal adherents of each school of thought will try to pressure you into their camp - "anyone could hear the difference" or "your system isn't good enough" or "no one can measure a difference" and so on.
The key is to not worry what others think. Experiment for yourself - it is pretty simple in this case to stream FLAC and WAV files of the same song back-to-back. Once you've decided what works best for you, run with it and ignore the naysayers.