I keep seeing comments like this when Kagi is brought up. One of them motivated me to try kagi about a month ago. I would love to replace google and try out every alternative search engine I encounter. I admit it will be hard to replace. I'm a programmer and searching is basically a sixth sense for me at this point. I'm frequently frustrated with google results but have never found anything less frustrating.

I signed up for kagi, ran out of the free searches in 2 days, my initial impression was "not better than google" and never looked back. I probably would have tried for a few more days if the trial was longer. Still more likely than not that I would have crawled back to google, but it did seem like not enough time to fully evaluate. For instance, the upweight/downweight feature you mention is intriguing but I didn't really get a chance to see any benefits of it.