Laz is a very effective format to store and use lidar/scan files. Also, the GUI is shown above, but I preferred to use the command line. I never used them to convert from one version to another, but I'm pretty sure it can do that. Generally, I stuck to version 1.1 or 1.2, depending upon whether I had RGB included.
When exporting scan data, I intentionally kept my versions lower so that I didn't encounter compatibility issues. las2las.exe and laszip.exe were my 2 favorite applications in the LAS Tools suite. If there is a version problem, I think you can use las2las.exe to modify the files.
