I think you have to "take what you can get" depending on where and when you are consuming music. For me when i am on the go or exploring new music Spotify is good enough. When I am doing critical listening such as at home or in the office I will use only FLAC. You just can't beat the convenience of having hundreds of thousand's of songs at your disposal, curated playlists, and recommendation engine to discover new bands and albums. It's a means to an end for me.
^Summed up perfectly. I try to get everything I possibly can in FLAC for my desktop rig and critical listening. When I put all my music on my phone I convert it to 320kbps lame (I'll probably update my phone's library and replace it with all 256kbps aac)
If I'm playing games or doing work I'll use pandora and other services because they are "good enough" if you're distracted by something else.