The Nordman 7's are a great choice. They also have Hakkappellittas (sp?) but maybe not in the Insight's size.
There's nothing inherent in RE92s that necessarily make them the best, but they've been tested to be the best known all seasons in terms of rolling resistance, at least in the Insight's stock size. My technical tire knowledge is very limited, but I believe that one of the compounds used to keep rubber pliable (and therefore able to maintain grip) at low temperatures also reduces rolling resistance. The problem with using too much of this in all seasons or summer tires is that they'd wear our far too quickly as they're too soft when warm. It simply wouldn't be acceptable to have tires that last only 5-10,000 miles. Consequently you need to take your winter tires off when it starts getting warm (let's say above 40F with any regularity) or they'll very rapidly wear out.
This is worth watching:
https://youtu.be/GlYEMH10Z4s