Use of any interface designer - is it worthy?

["Arthur Maciel" <arthurmaciel gmail com>]

Hi there.
I would like to know from you who have practice working with gtkmm
(specially from Murray - I've seen your projects) if you use some
program to help you with interface design (like Glade(mm) and Gideon)
or if you write your own code, including for the interface design.
The fact is I'm trying to create some projects to ipaq 2210 running
Familliar Linux and Gtkmm is fully ported, but I was developing using
Gideon, and I cannot see the horizon of re-cross-compilation process
of updated dependencies of Gideon into the ipaq, in a way I could
install it on the pda.
In resume, I want to know from you (who own many projects) if writing
the whole code is as well productive as using interface design
programs.

I'm intending to start serious projects, that's why the curious
question to see where I should spend my time and
attention.(cross-compiling or programming).

I appreciate your opinion.
Thank you in advance.

Arthur Maciel