Well, it would, and will be a major pain for people on dial up. But only if they choose to fly in the AvA or SEA while this map is up. But that would be a one night pain in the butt, because changing from the default tiles to PTO tiles increased the map size to about 30mb. These are all pictures from the Japan Terrain which I recently updated. Japan was 12mb and now with PTO tiles it is 30mb.
As far as frame rates go, they are the same, if not better, than when using a terrain with the default tiles.