Funny, we preferred the X-Ice over the WS. Plus they seemed to last much longer.
To be fair, where you're from, snow is an occasional, whereas slick roads are more likely. Buddies of mine from the GTA sold their winter tires when they got to Windsor, stating that there's no point because there's not much snow down in W-town.
They ate their words on some days during the freakishly snowy years, but generally the X-Ice would do better in warmer, well-plowed areas.
I find that the X-Ice worked to lower tread depths (3/32" instead of 5 or 6/32" on the Blizzaks), but I found that the X-Ice got to the lower tread a little quicker. Nothing scientific to back up that comment though.
The crappy snow/slush performance of the Xi2s is so concerning to me that I'm actually thinking of tossing ours for the Corolla with 6/32" left.