You bring up stability systems, which hasn't been discussed yet. I'm really a fan of people learning without them, but the floodgate is open so we may as well embrace it. A real benefit though is that they can add self-righting to pretty much any plane. With a system like SAFE, I could see lightly loaded Ugly Sticks becoming very good trainers. They can land just as slowly as a Kadet and handle the wind so well. As an added bonus, they make great aerobatic trainers once a pilot has gotten basic flying down.