Hi, want to suggest a small improvement.
I usually have many open files and they are showed in multi-row tab-bar. It has like 12 rows for now and it takes big amount of space on my 1920*1200 monitor.
What I would like to propose is to implement small button on the toolbar like in MS Office 2010 products, that would quickly hide/show the tab-bar.

I’m sure you’ve seen suck a behavior in Word or Excel already.
Let me know what you think.