NZBgeek? I'm honestly not sure. I currently use NZBgeek, and for the most part have been very happy with it. Lately, however, I've been running into some issues with articles no longer being available. I've tried a couple of different Usenet providers (had been using NewsgroupDirect - tried Newshosting and Eweka) to see if that would make a difference, and they didn't.

From reading around online, and specifically Reddit, Drunken Slug came up a lot as a good indexer. Some claim it to be better than NZBgeek, many say they're about the same. But most everyone agrees that having NZBgeek AND Drunken Slug is an ideal combination.

I didn’t find that to be the case. I let slug drop last year after running them concurrently for 2 years.

I’ve read they scrape each other from people posting on Reddit. Having done a lot of manual searches in Sonarr that certainly seems likely, there was nearly 100% overlap, at least for what I looked for.