Hey djtt

I'm a product design student currently working on designing a controller. I am trying to gather research and input from djs to help develop my design.So i have a few questions if you'd care to answer.

What controller/set up are you using?
what is your level of experience? how often do you use these.do you dj for recreation or is it a profession?
What made you decide on that/those units...how does it fit your needs?
what do you love and hate about them, what changes would you make if you could?

Thanks a lot
all your input will be highly appreciated