After testing more than 20 laptops with Whiskey Lake-U processors, the raw gen-to-gen performance advantage looks to be one of the smallest in recent years. If you own a Kaby Lake-R laptop, it may be best to hold off on buying a replacement until Ice Lake comes out later this year.
https://www.notebookcheck.net/The-average-Whiskey-Lake-U-laptop-is-just-8-percent-faster-than-Kaby-Lake-R.409376.0.html