I do remember Dundjinni taking what seemed like hours to export the final map. I ran some tests with MapForge, exporting a 10Kx10K pixel image in 24-bit color (uncompressed size: 300000000 bytes) and it took between 8 and 31 seconds to complete the export to PNG format. Exporting to JPG and BMP format took much longer, but was still very fast in comparison to DJ.