Wow, this was one long topic.
I will try to not beat on any dead horses here.
For me, trying out WAV vs Flac vs VBR MP3's I noticed that the biggest difference is actually between making a bit of effort in the MP3 making vs making simple low bit MP3's.
I have setup my dbPoweramp to rip to WAV - and from those files I make MP3's. Also, I have noticed a slightly better performance in some players between wav and FLAC but it seems that this is due to dated players having problems making the uncompression of the FLAC files and in today's stuff where FLAC is getting more and more common - I don't think anyone would hear the difference.
The reason for WAV is simply because I wanted a 1:1 backup copy somewhere and had heard taht wav were slightly better and that I got very far into ripping before figuring FLAC out
Most listening at home is wav based.
Another thing I noticed was that going from built in soundcard to a real DAC and Q701 make even MP3's sound great so the format should fit your needs. On smartphones and many mp3 players - you will be hard pressed to hear much of a difference at all since many ,smarthphones especially, simply sound not great to begin with.
To finish this, I wanted to thank everyone for a really interesting post - would love to read a dedicated piece on how to make the best digital files for listening for best quality, best sounding but smallest file size and something in the between. Also, for those that hear so much difference I either envy your systems - or your ears - or both
Cheers.