I use Kagi too, it’s surprisingly snappy! Like seriously impressive for a small org. They talk about speed optimisation being critical for them as well. I find the result to be excellent as well. A true Google replacement/feels like Google in its prime.

I believe they have their own index and bot as well?

Also using Orion! It’s the only one that’s convinced me it’s better than Safari, primarily because it’s actually more aggressive with power savings than Safari. The implementation to kill idle tab processes almost immediately is very effective imo.