The Original Folding is a versatile Reformer model, because not only can it be folded, but it can also be stored upright in an a-frame position once folded with the foot bar sitting flush on the floor to support.
The Studio and The Original are not designed to stand upright or on their sides and are instead intended to be in a space that is designated for the Reformer, where it does not need to be packed away.
*Please note that as with any piece of furniture that is not anchored to a wall, Reformers are a hazard to children. Ensure that kids are supervised to avoid them knocking the Reformer from its standing position and causing potential injury.