There were two reasons why I switched to Linux, first one you already mentioned, I got tired of viruses . Second, I have to thank the team at Microsoft for "creating" Windows 8 . At that point I knew that I'm not going to put up with the stupidity of that OS , so I switched to Linux and never looked back.

The reason I use Audio Pro9,is that it's very elegant and user friendly while working with MIDI files , and I prefer using MIDI, I tell you why. When I create a backing track on the BK-9, sometimes the arranger freaks out while I'm doing the chord progression, especially if you have a piano in the style, it creates some unwanted notes as you go from one chord to the other, even though I also slow down the tempo to 60-65 BPM, and it still does it here and there. So my option is to either go into the Micro Edit inside the BK-9, or load the file into Pro Audio 9 and fire up the piano roll or the staff view. That's all I need a DAW for, and for that Pro Audio 9 is more than adequate, but I'll might give it a try to that Reaper, since they have one version for Linux.

For creating music sheets I use Musescore 3, I can even save those scores as MIDI files, from there I can load them into the BK-9, and define the instruments to whatever I want it. With Audio Pro 9 I can load multiple MIDI files created in Musescore and merge them together.

If I need to manipulate audio files, I use Audacity . These soft-wares might be stone age, but this is what I know how to use, although it would be nice to have one software that does it all, instead of a bunch of different ones, each doing different things. That's why I was curious what other folks are using, just to get an idea.