Same here -- Windows for sound production, Linux for everything else.
For audio-only, I could get along with the excelent Ardour if I could figure
out how to use it. I have been using an older win98 operable Cakewalk Home
Studio, DX and some VST plugs and see no real replacement. The MIDI stuff is
a bigger obstacle. While in an NT mode (avoiding thunking), I can almost get
some of this to work in WINE, the registration schemes, special dialog
layouts, etc., usually mean no-go.
One app that may work in Unix if "HarBal", a mastering re-equalizer. The demo
works in Linux using WINE 100% and the author promises a Linux native version
soon. This is NOT opensource (neither is all the Cakewalk and Steinberg stuff
we long for in Linux).
Other stuff that WINE runs are:
Tabledit -- a tablature editor/player Also has a player-only variant.
Abcmus -- an ABC file player-editor. Just clipboard the ABC in!
Jammer Pro -- will work (NT mode only) but its style-loading dialogs are not
totally functioning. Usable but barely so.
dbPoweramp -- niftiest wav-mp3 converter around and free. Under windows works
on right click, under Linux just as standalone.