Since you asked - 

What do you think of the new UI?  - I don't like it.  The previous view with the alternating colors and larger icons was easier to read.  Why is this all black and white?  And the font seems smaller?  Can we have an option to use the old style?

What’s unclear?  - How to launch and use the non-IE recorder was incredibly unclear, at least for me.  I could only get it to work by using Test Studio, not the plugin, and by clicking Record on the project view.  I didn't see this in the Help.  

Are you having any problems installing?  - No problem. 

Any problems upgrading and using existing projects?  - My elements list was/is empty on Test Studio, although it ran fine.  And the list was populated correctly in the Visual Studio plugin.