Its an advantage to have them further away if ppfd stays the same; less heat radiated from the light towards cannopy (though this is relative, some situations you want the radiated heat) and more space to move air over the cannopy, easier access...
Edit to amend: there is no real negative in having higher hanging height but theres a negative in needing higher hanging height. Also, in practice theres always height limitations, be it in a tent or an open space: the taller you can grow your plant the thicker your main stem, the more it can drink and the more buds it can grow. Also in an open space the higher you have to hang your light the more of the light is lost to walls, but generally in a tent with reflective walls you dont have as much loss. As long as your hanging height doesnt affect the space you got reserved for plant growth the higher it is the better, ppfd being the same, but this is a very theoretical situation that generally never happens unless your wasting some watts.