AMD Radeon™ ProRender is a powerful physically-based rendering engine that enables creative professionals to produce stunningly photorealistic images.
Built on AMD’s high-performance Radeon™ Rays technology, Radeon™ ProRender’s complete, scalable ray tracing engine uses open industry standards to harness GPU and CPU performance for swift, impressive results.
It takes some time for the image to clear up after they stop moving, we’ve had GPU renderers like that for a long time, it’s useful for previews but it’s not a realtime renderer.
The lag kinda looks a bit worse than Vray RT, Iray, MODO or other “accumulation” renders. Generally those apps will update even if you don’t stop moving the camera. Not a huge deal, but being able to move the camera and it be a bit more responsive does make it more interactive.