Funny thing, I have never cared much for serrated knives (except for cutting crusted bread), but I did have (don't know where it went) a Ginsu utility knife for many many years that I used often for a lot of kitchen chores, it never got dull, I used it to cut open food packaging, bottle seals, frozen foods, butchers string, all the stuff you wouldn't want to subject one of your "good" knives to, and it never needed attention.
I'd almost forgot about it until I read your post, every time I visit Sally's or other thrift stores I look in the used utensil bin hoping to find another.