Unfortunately it does not seem to have the accuracy, or breadth, of the old hnsearch.com. Hopefully this will be fixed in time, but I have found it lacking relevant results and myself switching back to hnsearch on most occasions.

I also wonder about all the other small applications in the "HN ecosystem", like karma tracker, that rely on the hnsearch API. I see that algolia has an API, but will those other projects just die too?

That explains why I noticed a couple of things off on my aggregator. I was using hnsearch.com/rss which recently seemed to have been alter and is now missing most of the data I was actually using.