Its more for me personally to know another DAW so I can use as many as possible and be ready for whatever situation might arise.
If an artist has a DAW session, I could just open that instead of tracking it all out and then starting a new mix project.
I know Cubase pretty well now, FL Studio, Acid Pro, Reason, I used Pro Tools a while back but its changed a lot and I cant remember it now, but shouldnt take long to pick back up. I should learn Ableton too and stop being put off by the graphics, lots of people use that too.
All DAW's do pretty much the same things, just in their own ways, ways which may or may not suit different people and different workflows. Once you know one, doesnt take too long to find the tools you need to get the job done, and then learn it more deeply as you go. Never know, it might become my new favourite DAW, if that happens I will certainly say so.