It has been almost a month since I moved over to Umber. My shop used up 4000 land impact and my Yelapa home a few hundred. That left me with plenty of "prims" leftover. By now we all know that prims and land impact points are not equal --- but saying "prims" just flows better off the tongue :D. Any way you look at it I used up about a third of my total land impact points on flora, rocks, landforms, shrubs and trees.
And its looking pretty darn good.