Backups: how much raw system stuff can be transferred to a different computer?

Okay so assuming I can make a full system backup, all origin data is there, how much system stuff (like not in home which seems to be 100% transferrable) could I put on a new computer if I have it in raw form from rsync? Assume I can put any OS on said new thing to start. What would be in home anyway as far as settings and app data? Sorry I ask many questions here and do not answer much. I have an Ubuntu Pro desktop version of Ubuntu in case it helps. I doubt I can find this model and exact configuration of computer again, Lenovo Thinkpad T460 in case that helps. I would likely put Ubuntu on new one to start. X E.