All licensed tools can be tested for free without a license. Just download the full package with or without GUI and run LAStools with the „-demo“ argument. For quality tests, use small samples up to 1.5 million points. For performance tests, use point clouds of any size. Output distortions (e.g., noise, diagonal lines) are related to license protection.
Sample command of a large DEM creation using the demo mode and multi-core processing:
las2dem64 -i *.laz -odir output -step 0.5 -use_tile_bb -cores 16 -demo