I don't have a 1x30 but I do have a Delta 1x42... No, it's not ideal but this is a hobby for me and it's what I could afford. I am a med student and when I'm not in school/studying or spending time with my wife and kids I like to have hobbies that have nothing to do with med school and knife making is my primary hobby. We live in an apartment and I only have our small deck to work on, using a tarp-covered chest freezer as my work bench. I have a set of plans for a NWG but it will be years before I will have the money to put one together - sure it would be fantastic, sure it would improve my knives dramatically but the truth is my money goes to tuition and diapers so I'll make due with my gutless, weak, too fast Delta. My next project should be replacing the platen because holy crap is the stock one awful!
I know your original question is what are the best uses for these underpowered grinder-wannabes and for me, right now, the simple answer is everything.