Hey there!
Im using the 1.7 version and the Web-Mercator 3857 projection.
When I zoom too close with the ArcGisCamera (With the ArcGicCameraController) the map starts to look like this: 
Which is terrible, since I need to zoom close to the map, if I zoom out it gets better.
Is there any solution for this? As I said, I can not zoom out to avoid this issue, my whole game idea is based on viewing the map closely. I also can not change the projection to lat/lon (With lat/lon the issue is not there btw).
Anyone having similar issues? Some feedback on this "bug" would be great 🙂