I don't get the praise over GitHub code search. I find it very inaccurate and often missing references etc. Maybe it depends on the language you are using it with? (Go here)
Have you tried the new search that was just launched? It seems to have significantly improved search accuracy. I agree the old version wasn't that great (though still was one of the better options for finding usage of things in the wild like rarely used OSS dependencies I needed to debug).
I was in the beta, which im assuming was the same. I find it sometimes misses references in the same folder as the file I'm look at when I do reference search.