FLAC should sound the same as the wave file but it doesn't. It is lossless, which is great, but, unlike Wave it is not a native format to Windows (or Mac) and as such it makes the CPU work much harder than wave does. Resulting, depending on your PC/Mac's spec in noticeable degradation compared to Wave.
However, if you have a good quad core Intel or AMD CPU you shouldn't notice anything beyond a very (very) slight hardness.
I use an analytical engine running VirtualBox to run Windows to listen to music, so any excessive processor usage is directly audible.
Apologies in advance if this violates TOS8 somehow, but I have to say that people who make statements like the original quote understand neither how audio encoding, lossless compression, nor even a computer works.
By the way: that same argument (increased sys load) could as well be used against this audiophoolish Hi-Rez mania!
The offending statements in the quoted post have been removed by one of the Moderators over at AVForums. It is still full of subjective opinion, but at least the technical nonsense has been excised. Small steps......