Daggy:

I'd say it denotes cackhanded and unsophisticated with perhaps a touch of plastic pocket protecter (not that they're not a fine invention- for those of you not in the U.S. that's a plastic pocket you put in your top shirt pocket to prevent pens from leaking on your clothes).

Unfortunately I fear the etymology of the word harks to a great sheep raising nation. "Dags" are the bits of wool soiled with dung that you need to cut away from a sheep's behind for it's health and well being. This process is "crutching".

The OED cites a dag as an extraordinary person or a tough but amusing person, but I have never heard it used that way, it's always mildly perjorative, but usually in a friendly way, like "dork"