Bitwig just got released. And it works very well under Linux.
That's cool, I never could motivate myself to reboot under windows just for Protools. I recorded a few things but I did not get motivated enough to learn seriously.
Now, I have the setup of my dream:
Bitwig + Komplete Audio 6 linked to my 11R with SPDIF (yes, no driver for USB audio with the 11R, rotten avid...)
And of course ElevenHack
I even could make Steven Slate Drum 4 plugin work with a vst native bridge.

Bitwig, for a noob like me, is amazingly cool. I am very happy with this new setup. Next GAS: a cool midi control surface (Nektar p4 ???).

You can try Bitwig, there is a demo. It has been created by Ableton ex-employes.

Yaaaahahahaha cooooool! <-Happy!

(I am sooo happy that I am even reading the 300 pages manual to learn every details! THIS is motivation!!! )