I read there was no difference and ripped all of my disc to flac. I never bothered to test. Yesterday, a friend played several different files of the same CD, one wav the other flac. To my surprise, I could hear the difference for most of the recordings. On one, I could not for whatever reason. The flac had both a loss of detail and "air." I should have asked my friend before I started to rip. It would have save me some time.
Admittedly, it is a subtle difference and takes a very revealing playback system to show the differences, which are pretty much as you describe.
As I mentioned originally, it's NOT a problem with FLAC at all, as a FLAC file will uncompress to its exact original WAV. It's only when the FLAC is played back in real time with a plugin in most players, Foobar, Media Center 17, many others. And it's not something you'd be able to hear on an iPad or iPhone as mentioned in some articles.
When I first heard people talking about this I was positive there could not possibly be a difference (playing a FLAC vs WAV in real time). But when I actually tried it and really listened, it was quite apparent.
Although it's a lot less convenient, I use JPlay Mini, which decompresses the FLAC first, and then loads the tunes into a system buffer. On this player playing FLAC sounds just like the WAV equivalent as heard in other players (or itself). JPlay can also be used as a player type in JRiver's fine Media Center 17 software.
If you're just casually listening as I am right now, the differences aren't bothersome, but they are definitely there. I store everything in FLAC and uncompress it either with JPlay or manually before serious audition.
--Bill