I use Linux since the late 90ies (when it quite frequently happened that after booting your GUI was gone). Over the years I tried different distributions (Slackware, Debian, Ubuntu, Crunchbang, Arch) but I am now using Mint with OpenBox. I canāt help it but I still feel like a beginner (although I am not after about 20 years
); this is probably due to the fact that Linux kind of forces you more to get to know the system as other OSes - you have to make your hands dirty at some point but on the other hand I am no expert at all and more of a user than a programmer.
I also have a rather old iMac, which I sometimes use for working with Photoshop. Actually this is the only program I miss on Linux because I never bothered (and I donāt want) to get used to Gimp. Apart from that I never ever miss anything on Linux - at least not anything which I could get from using Windows or OSX - besides the mentioned exception.
Audio on Linux is probably still a construction site and I find myself sometimes struggling with it. On the other hand: If you get aquainted with Jack and your system runs stable it is generally easy to use and works well; I know, this is kind of inconsistent but does exactly reflect my feelings about it. I am a long time Emacs user (actually Spacemacs since a while) and though also here I am sometimes struggling, I have no intention to use something else.
For audio I sometimes use Audacity, I really like Sonic Visualizer (for analysis and quick sample editing), Helm as softsynth (keep an eye on its creator Matt Tytel, he is about to release a very interesting wave table synth called āVitalā sometime next year, see here if you are interested), from time to time ZynAddSubFX (or Yoshimi) and predominantly Sonic Pi (which currently you will have to build on your own on Linux). I can recommend Carla by falkTX (who by the way is also the current maintainer of Jack) as plugin host.
I find it quite difficult to think of a reason to convert to OSX (actually Apple and its universe has become an unpleasantly closed system during the last years, which I really dislike) and I can by no means think of any reason to use Windows again.