I use it. It works fine for me. Idk if it is a big improvement, but it seems better than the old way.

I use it a lot (don't use the file menu many anymore) and I'd love to see the option in the preferences that it opens automatically if you close a song ... a keyboard short cut would do as well I reckon ...
 
Another helpful one would be to add a right mouse menu option which allows the Start Screen to "forget" about some projects i.e. when I save manual backups, it would be nice to drop the older versions from the list ...

When you save (save as) a new version of your project, it would be really nice having  automatically pinned this last version in the start sceen and having automatically unpinned the previous one .

The Start Screen was a really nice and helpful addition to Sonar 

I wish the new from templates would be ordered by most used....

meh
I wish the new from templates would be ordered by most used....

I think that is a good idea

Zargg

meh
I wish the new from templates would be ordered by most used....

I think that is a good idea

I use a custom template location which has only a short list of useful templates tied to my setup...

The one thing that would cause me to use  the start screen, is to replace the almost useless automatically generated thumbs with my own images.  That way, they would have meaning to me, and visually I could pick out an older project. 
 
Just my 2 cents.