I am often moving between three different computers and use my iCloud account where I save all the Xlights files. Works very well. Dropbox, Onedrive etc would do the same. However, I think its a good idea to keep backups of the xlights_rgbeffects.xml, xlights_networks.xml, xlights_keybindings.xml files in a separate place every now and again as cloud storage systems overwrite and update files on all your devices everytime you make a change. So it is possible if on one device you somehow muck up, say, your xlights_rgbeffects.xml file, for example, and save it to the cloud, all the other devices will be updated with that bad file (speaking from experience here

).