I looked at the link and would have a couple questions about these. While they say they are legal in all 50 states, do they qualify as chains when you hit chain required mountain passes? My other main question would be wanting to know more about how they perform on ice. Regular chains have a fair amount of bite on icy roads which is where I've always found them to be the most beneficial. I generally have tires with a pretty good bite in snow, and find that the roads generally get closed before I run out of traction.
As for your trip in May, that time of year, while you may encounter mountain passes where you're required to carry them, the odds of you're having to chain up are small. Should you get a snowstorm that time of year that require you to chain up, you can generally just hole up for a day or two and the roads will be cleared. The super slow speeds you have to drive when chained up result in your not covering much ground anyway.