Not all may be new to v6, but I'm just noticing them.
In Windows, if you have more than one tab open, it creates 3 instances on the task bar. Makes it 2 clicks to reopen. No big deal - I'll get used to it.
In the What's New page, it mentions quickly toggling between raw and jpeg preview. I can't find that toggle.
In full screen mode, it would be nice to show lost shadows and highlights at the same time.
So far, so good - not seeing many changes. Can't say that it is faster - it was already fast.
One thing I would have liked to have seen is one click to open a new tab. Maybe one click is a toggle for a single tab, and double click opens another tab?
Keep up the good work!