I’ve been playing with Microsoft 3D Builder for Windows 10. It recalculates heightmap projections so quickly you can jiggle your mouse or your finger on a touch screen and jiggle the image. That helps with spotting features.
The software is free and apparently only runs on Windows 10. It took less than two minutes to install and only a few minutes to figure out. It is designed for preparing images for 3D printing but it works well as a quick visualization program. You can rotate views and change viewing angles by simply dragging the object on the screen.