The major update of the compact 2020 ThinkPad X1 Carbon is the more compact power adapter. You also get new processors, but they do not offer a performance advantage. The new X1 Carbon is once again a very good business laptop, but you can just get the previous model and save money.
https://www.notebookcheck.net/Lenovo-ThinkPad-X1-Carbon-2020-Just-get-the-2019-model-and-save-some-money.479524.0.html