Hi Rod,
Yes, I did try once in test environment and works fine unless you do not have used your custom CSS. In my test case I ran on one with one of our project but saw many places got screwed up, However those can be fixed because mostly effected areas are where custom css compatible with older version does not work. AwareIM forms, grids and other views mostly run fine. (Definitely later version has much more clean UI)
Some components does not show properly like Image Uploader on AwareIM form, so might have to put some css fix on that... if you have good hand on CSS then you can try with your app.
At that moment I do not have time to upgrade all changes so never went into that direction.
Bootstrap themes link which you shared are really cool and we already have started working on one of our project to make this transition happen.
Hope will able to share soon!
