I think if you're getting "very poor" service THAT often, there's something wrong with your standards. I've only ever had one server who did a bad enough job that I purposely left a BAD tip (and if you leave no tip, chances are the server won't get it, and will just think you're cheap). That server did about every possible bad thing - took our order, forgot about us for an hour, never put the order in, took our order again, got it WRONG, spilled our beverages on the table and didn't clean it up, and ignored us the rest of the meal. That's reserved for the you-have-got-to-be-kidding-me bad.
Even then, I wouldn't speak to a manager about it. Anybody can have a shit day, and for all I know, her dog just got ran over 5 minutes before her shift and she just found out she has cancer, and who knows what. But I'm not going to reward her for a job that badly done. If it's repeated behavior, or something REALLY inexcusable, deliberate, like calls us a bad word, or something, that's when I'd say something to the manager.
CLEARLY with the lack of agreement you're getting here, the general public does not share your "standards of acceptable service" so if you want your waiter to refill your water glass every time it gets to 3/4 full, by all means, say so at the beginning of the meal. And honestly, if someone had said to me at the beginning of the meal, "I expect x, y, and z from you" maybe I'd have thought they were a nut, but I'd have DONE it.
If you're in a hurry, ask for the check to be brought to you with the food, so you can pay, and leave when you're ready. Not knowing you were in a hurry is no excuse for the waitstaff to take forever in getting you your check, but if you want it fast, just say so. Save yourself some trouble. Stuff like that, some of it's on you, the customer.