Hi,
WPF is a b*tch and you'll start to hate it real quickly but it is a much better choice. I will never return to WinForms. You can do so many great things when you have more experience.
Thinking about avoiding problems in my first project, I will consider using WPF in the next time.
You can have a look to this modest contribution about user interfaces with AutoCAD .NET.
Excellent tutorial!
I will definitely revisit it in the future.
Thank you for sharing your knowledge.
I've used winforms in the past due to its simplicity.
My user interfaces aren't complicated so I followed the keep-it-simple-stupid approach.
They also fit nicely in with most of autocads own user interface menus as well.
Even though I know that WPF increases the possibilities of personalization, I will use Windows Forms because I am used to its use in applications outside of autoCAD.
I believe that this way my performance will be better initially. I hope I'm not mistaken.
Thank you all for the answers.