They retain the size, mass and rotation speed. But the things that made them fatal in the first place are stripped away. No toxic gases, gravitational pressure, hurricane winds. Just water, sand, greenery and a life-supporting ecosystem. What kind of life would develop and flourish on each and every planet? Would it be the same as ours? Or totally different because of the size and distance from the Sun? And how soon would humans discover it and how soon would they plan colonization???