Personally can't stand "How's it's tasting?" It's pretty idiotic considering what the job entails.
Seems to coincide with general restaurant service deteriorating. Come to table take orders, bring order, bring check but making sure to stop by to ask "How's it tasting?" But won't refill drinks, take empty plates or stop by more than once during the middle of the meal, maybe. Usually they will ask "How's it tasting after a few bites, never to be seen again until they bring the check.