Vectorial GUI is the way to go, check out the new FL STudio BETA 12
http://www.image-line.com/flstudio/flstudio12.php
Flexible and simply amazing I find. And it looks to me if you check FL Studio, Meldaproduction plugins and even Presonus new
http://www.presonus.com/products/StudioLive-RM-Series looks like all based on Vectorial and it gets that Flat UI that is more cleaner and easy on the eye. And what I love most is the fact that it's Sizable in any way you wish ;-)
All this to say I'm loving Vectorial UI