Here's what the "stair case" effect looks like in Vue. On a MEGA Terrain it is much less noticable- but on smaller terrains it is VERY noticable.

O.K.- WHY NOT use DEMS? There are lots of them on the NET, etc. Well- they work o.k.- but to my own mind- importing a BITMAP of a Terrain looks MUCH BETTER. Plus, you have the options of using Image Editing features on it like Resize, Image Grayscale Levels and Unsharp Masking (I don't recommend Unsharp Masking on anything other than MEGA 4K Terrain Bitmaps as it can create unwanted SPIKES in smaller terrains.)

In fact- you still might want to hit the Fluvial, Thermal, etc. buttons once on an imported 4K Terrain to make it slightly NEATER looking. But too much and it will start to change its shape...