1st I'd tend to stick with what I know, and for you that means Yokohama. Me I've done well with Michelin's, but there can be significant differences based tire models, the size of the tire, the car they are mounted on, and the driver.
I have no experience with the Defender offering from Michelin. I recently put a set of 4 Michelin X-Ice 2 on an '03 Honda Civic. Great tire for a winter tire. Very quiet (and that is great for Honda's which tend to transmit tire noise into the cabin), great smooth ride, softens the bumps and expansion cracks well, great dry and wet traction. Snow and Ice are yet to be determined since have not encounter those conditions yet.
My guess is the Defender is using a similar base with different rubber compounding and tread design. I'd expect it to be a good tire. Since Michelin is pushing the number of miles they will go, that would not help winter performance due to harder rubber and less open tread. I'd expect a good 3 season tire of the Defender, but not very good performance in snow and ice conditions.