The looks are not that great but Foobar works in Ubuntu through Wine (and I did not even set up the tweaks recommended by the geeks).
I am not using it all the time. The point of Foobar (just like that of Firefox) is to use it with a lot of add-ons, and so it can get heavier than other players (not that bad, over 60mb), the "facets" feature doesn't look as it should and often Foobar may freeze or crash (I should have made those tweaks!).
I use DeaDBeef player instead when I want simple access to my music library, or a lighter player like Audacious, Quod Libet or qmmp (and why not VLC or SMPlayer) just to play files or radios. But when I really need thorough access to something in my library, Foobar is the way.
A lot of the other features of Foobar are there to try. I did not have the occasion to try too many. The tagging feature seems to work.
I was pleasantly surprised to see that the converting ability of Foobar is working in Ubuntu, and can be used to split big single disk or album files according to the cue list. In Windows I was not even using Foobar for splitting, for I used Medieval cue splitter, but in X(ubuntu) I tried it in Foobar and it's even simpler! Just load the cue file in a playlist - as if to play it: and it should play in Foobar - then select all files and convert them the usual way. Foobar sees the original file as multiple files and converts accordingly.