With a sufficiently high bitrate, and a detailed enough codec, you may as well not be compressing it.
The problem with the comparison between an MP3 and something encoded with FLAC is that you're still working off a digital source. By its very nature, the digital source is lossy -- it's limited by the original sample and bitrate. You can offset that by using a high enough resolution on the digital source, but ultimately, there's still going to be loss of information, no matter how high a resolution you use for the source.
As for audiophiles, I identify as one. I do prefer FLAC for archiving purposes, because I'm not hurting for space, and because it allows for a much higher bitrate than MP3 (and my stereo plays FLAC natively), but I will also qualify it with what I consider a far more important distinction : you will get *much* more mileage out of a good set of speakers than you will from going with FLAC over MP3. There is absolutely no reason at all to go with FLAC over MP3 if you don't have hardware that can take advantage of it. If you're listening to it mostly on a cell phone with shitty ear buds, then there is absolutely no reason to waste space on a high resolution recording. Similarly, if you don't have a stereo that can play FLAC natively (since even passing the sound over an HDMI link will cause the signal to be degraded), and you're not pairing it with good quality speakers, then it's a total waste of space. And no. That $1000 set of speakers you bought at Best Buy is *not* a good quality set of speakers. That's not even close to high end, when it comes to audio hardware.