I have been a longtime Spotify user, ovee four years at this point. I love the app, and the music and selection is excellent. Are there acts I wish were on there? Yeah, mainly Prince, Peter Gabriel, Bob Seger, Garth Brooks...
That said, I have given Tidal two different chances. Once a year ago, and once last month. First try, I could not tell a difference on audio quality even streaming lossless. (I chalk that up to my LG G2) Last month, using my LG V10 and good headphones, yeah I could tell a difference on some tracks. For the majority, however, they sounded identical to Spotify extreme quality. Additionally the app does like to crash, and my wife would routinely have to restart the program on her laptop as it would stop in the middle of tracks and be totally unresponsive.
I do like Google Play and use the free storage to hold my tracks that aren't streamable (examples above) but I am not a huge fan of its interface.
I think you guys are right when you say it comes down to user preference, and at the moment mine is Spotify.