Welcome to GPLDL - we are still beta - please report any bugs via the contact form.
Is a god idea put a search field in the repository.
I agree, at the moment I use the Firefox browsers built-in find feature to narrow down the search. So a good site search option would be really good to implement.
Search is finally here (in the sidebar). This is still beta but already working pretty well. Please let us know via the contact form if you experience any difficulties or strange behavior.
We hope you enjoy this feature!