Is your hub slipping? Not necessarily. If both your lockring and cog aren't tightened enough, you'll get slipping when you accelerate (cog slips forward until it's tightened down all the way) and when skidding (cog untightens until it's caught by the lockring and the lockring gets tightened down).

Is your Quando hub junk? Probably. Most people don't give those or the Suzue jr.'s a second-thought because Formulas are so much more superior for practically the same price.