This is the reason why you should give a try to Full Next Search:
I am currently running a max scale indexing test with Nextant v2 (Full Next Search) using 1TB of data, split in 100,000 files of 10MB.
While indexing with Nextant required GBs of RAM, Full Next Search only use few hundreds of MB.
How to install Full Next Search
Also, neat feature from the Android team (work in progress)
Beside indexing performance (Solr vs ES) and that Nextant is at EOL, what are the other differences between Nextant and fulltextsearch.
I ask because I have used Nextant for about a year now and I think it is awesome.
Few features from Nextant are not yet available in Full text search, but Full text search will get more and more love (ie. features and bugfixes). Some of those features were expected for a long time in Nextant but could not be easily integrated (like searching within the current directory)
Also, Full text search is officially supported by Nextcloud and well better integrated to the core.
On top of that, Full text search is conceived as a library and can be integrated in any apps that generate content (beside the Files app).
If Nextant is working fine for you, you can keep it for the next few months, but I will make you switch to Full text search 
Thank you @Cult for the outstanding work you have put into it. I love Nextant and use it frequently, but it only makes me more curious about what to expect in full text search.
I started using full text search on a test VM, and I will wait a few months before taking the plunge.
