Hello Fred,
The tires, I have to say, have not let me down at all so far. I can get a good lean out of them at any speed up to about 70 or 80kph.
I've ridden a few hundred kilometers in the rain and I've never experienced a slip, however, riding in the rain terrifies me and so I naturally ride more slowly and don't put much of lean down around corners. I'm no expert but I'd say that white road-paint is the nemesis of any tire, good or bad. I only ever ride over it when I have to, and when I do, I don't accelerate or alter my course (taking the surrounding traffic into consideration first). If I were riding a beasty 600cc bike with a rear wheel that is more than twice the width of that white line then I may not be so cautious of it.