...how well it really works, I don't know.

All of the hardcore gnome hackers that I've spoken with seem to come to the same concensus: use the .glade file, but not the code.

Personally, I don't mind the C code glade generates, but most seem to disagree. The Perl code that can be generated via glade is done with glade2perl, which is a Perl program that makes heavy use of Glade::PerlGenerate. IMO, the code that it generates is absolutely hideous! I generally hand-write my own, but have been meaning to try libglade (see below).. and'll be glad to let you know how it is if/when i do.

As far as peoples' distaste towards glade generated code... it seems preferable to just use libglade to dynamically generate the UI from the .glade xml file.
I believe (but am not sure) the Perl binding for this lib is Glade::PerlRun, though I've never used it.