Its not REALLY cold here, but it was 22-25 farenheit so I guess that falls into the -7 degree celsius category. I can't recall whether or not other storms I've driven the car in have been that cold but I doubt it, we really don't usually get that cold here and when we do have snow it stays around freezing. I did take our Prius out right after I got home for comparison and it did much better on the stock Goodyear Integrity's, all the same VSC equipment and FWD. Bear in mind that the sideways pulling on takeoff is DESPITE the VSC, just like the LS does. Never had that with the Bridgestones and didn't get that with the Prius. Air pressures are all fine. Steering stability was also not as good as the Prius but the Lexus is a lot heavier.
Not really possible to alter my driving habits, I've got a lot of experience driving in the snow and my experience today was happening while I was being very careful because of the poor traction.
I've been searching around and I can't find any serious complaints about the tires in the snow, if everyone was having experiences like these trust me you'd read complaints all over the place...
Maybe it was just a combined set of variables that reduced the tire's performance. Different rubber compounds would react differently, and different brand tires have different rubber compounds...