In some situations it’s night and day - take this ‘stained glass window’ type scenario. regular path tracing can’t handle this at all - yet path guiding can easily.
This is just the straight glass shader with voronoi driving the colour. Zero roughness, clamping and filter glossy both zero too. 500 samples.
In this case - I found PAVMM to be much better than Directional Quad Tree or VMM
