I've owned and been driving on Kumho KW-19's for around 4 years. Currently on my second set (215/65R16's) and I have them studded. There are several advantages of these tires over Michelin X-Ice and downsides as well.
Advantages
1. Superior snow traction. These tires are designed first for snow and slush, second for ice. When you add studs (as I did in mine), they are a very well balanced tire for traction, both lateral and traction.
2. They are priced around 10-20% less than Michelin and Pirelli Snowcarving.
3. Four winters of driving. High treadwear rating.
4. Extreme cold weather. These tires are superior in all aspects as they retain excellent traction.
Disadvantages
1. Dry pavement traction. As with all studded tires, the traction, especially lateral.
2. Noise - studded tires are very noisy on dry pavement.
3. If you live in a climate where you have mostly dry pavement, I would probably recommend the X-Ice or other similar 'ice' tire.
Overall
I would only recommend the Kumho's where you get lots of snow and ice during the winter season. Especially for mountain and northern locations (northern Europe, Canada, and high-elevations in the USA) where the temperature hovers around -10C daily (and extreme freezing).