Drowning and desperate. This is that "utterly out of control" feeling, the sense that you'll never, ever be able to catch up. This is the source of big backlogs of email and paper. Work is falling through the cracks, and you have a reputation of "Better follow up in person or it probably won't get done." Grievously unsustainable
Sinking (maybe slowly, maybe fast). This is the sense of "I just can't quite keep up," and leads to an overall anxiety about work. Your inboxes are increasing, with occasional "binge" emptying happening. Unsustainable
Steady state, but brittle. You're just able to keep up if it's "a good day," but the slightest lag in work means you start falling behind - a day or two, say. And vacation or a trip? You'd better block out a good chunk of time blocked out to pay your "vacation tax." Brittle (one of the 10 GTD "holes" I identified)
Smooth sailing. You've got some amount of buffer built in to your life. You can afford a few days of letting things pile up, and emptying is not usually a problem. Sustainable
Couch potato/proactive monster. You have plenty of buffer. You can take off a week or two, say, and catch up with no sweat. Coasting
