2) Consistent. I have tried some brands, that personally, I think it is impossible to work with them. They are too brittle or soft and the only thing you get is that it breaks as soon as you are going to pick it up from the table. Better use one that is not so fragile.
3) Elasticity: it must be elastic, but without being excessive. There are some brands whose elasticity makes the previous point happen, they break very easily. On the other hand, there are others that allow it to be stretched and stretched without damaging it.
As you can see, there are not many qualities that it should have from my point of view. Although as I always tell you, it is useless to use the best fondant in the world if we do not know how to handle it.