They are better if you already plan on delidding the chip anyway due to direct contact and with liquid metal.
However if you have a poor chip anyway then delidding probably isn’t best advised as you will lose out on warranty for littler performance benefit.
You would probably be best asking in the cpu section on the 9900k thread where a few have them fitted.
They can have clearance issues though depending on the blocks and such as there’s is no longer an IHS.
Ocuk have the 9th gen derbauer ones which look to be of better construction and quality. I have one on the way for mine as I already have it delidded anyway and with custom loop so be interesting to see the differences.