To avoid being distracted by the gmail inbox and to have a clean composition interface, I always keep this URL bookmarked, and it still works w/ the new compose:
https://mail.google.com/mail/?view=cm&fs=1&tf=1&source=mailt...
https://mail.google.com/mail/?view=cm&fs=1&tf=1&source=mailt...
By right, I mean a clean, simple interface that you don't need to judiciously learn over dozens of hours of frustrating trial and error or by googling in support forums.
The old gmail UX was fine. In fact, compared to the new compose it was the bees knees. It takes humility to be able to realize that. But Jason wants to leave his mark - unfortunately the mark is an ugly smear.