Minor bug:  when the control bar is 'floated' the progress window for bouncing is hidden:  "Mixing down audio ..."   I had wondered what revision had done away with the progress window, and accidentally discovered that if I hid the control bar it returned. 
 
Minor feature:  one of the oldest frustrations with the X series was the inability to change a patch number directly in the Event List without calling up the crude and inefficient Bank/Patch Change dialog; and you can't enter a number directly in the patch number field because numbers cause screenset changes.   HOWEVER, new feature:  if you type your patch number as a negative (beginning with the minus sign on the regular keyboard and not the minus sign on a keypad) you CAN directly enter a patch change number into the field.     Weird, but useful undocumented feature.

Thanks for pointing that out, WC!
 
I'm reminded of one of the guiding principles of software development: if you can't fix it, call it a feature.
 
Corollary: Features are nothing more than documented bugs.
 
Not beating up on SONAR. It's WAY bigger than anything I ever had to code professionally, and I was certainly not "bug free." 
 
EDIT: Truth be told, a water utility control program I wrote over-pressurized the system and blew a moon crater-sized hole out of the main highway through the town (Dekalb, IL) that took out 3 of the 4 lanes. Fortunately, the problem turned out to be the utility's engineering consultant's design that was at fault. My program correctly implemented his faulty design. Got lucky on that one. 'Twould have been muy expensive for me otherwise.

Thanks for the great real world example!   Luckily I never designed for keeping-people-safe!   (Though I feel quite sure that "keeping people safe" and "code in the most crude and ineffective way possible" were close bedfellows and probably still are).

TheMaartian
I'm reminded of one of the guiding principles of software development: if you can't fix it, call it a feature.

That's a load of codswallap. No such thing as can't. If you won't fix it bring out loads of other new features so they forget about it. Or distract them. Or tell them to stop complaining..

Tell them to stop complaining. I like it.  Marie said, after all, "Let them eat cake".