Never had any strict trouble with it. Maybe it's just that I've used it for a long time but I enjoy the simplicity of using it.
My biggest complaint is performance for certain use-cases. Say if you're trying to pull a lot of attributes on hundreds of thousands of datoms it's going to be rather slow (even though it's supposed to be in-memory already). But again for these kinds of use-cases I'd probably go with a completely different kind of a database either way.
The story around deletions/excisions isn't that great either. Honestly the whole log/history aspect of Datomic sounds nice but never really used it other than for reverting stupid mistakes.
The #1 thing I love is the freedom of querying you get with Datomic. You insert your data in a way that makes sense for your data, and querying is pretty much a completely separate concern. For the most part you don't need to structure your schema around the querying capabilities of your database which I love. Say back in the day I liked Mongo because you could just insert whatever you wanted [0] but eventually you'd hit problems where you couldn't easily query your data (maybe it has changed over the years, no idea).
And the syntax is just a pleasure to work with. I'd love a version of Datomic that kept the same interface but dropped some of the more esoteric features in favor of performance.
Also I noticed some of the people reporting issues used the cloud version. Never used that so can't speak to that. On-prem is free and has all the features. As long as you don't redistribute it there's no problem.
[0] Yes in datomic you do have to have a schema. But it's pretty much a simple global list of possible attributes. If you need to add something later or make a change it's pretty straightforward.
FYI, Datalevin has faster queries than Datascript, for Datalevin has given up "database as a value" doctrine that both Datomic and Datascript share, so Datalevin can cache aggressively to achieve better performance.
My biggest complaint is performance for certain use-cases. Say if you're trying to pull a lot of attributes on hundreds of thousands of datoms it's going to be rather slow (even though it's supposed to be in-memory already). But again for these kinds of use-cases I'd probably go with a completely different kind of a database either way.
The story around deletions/excisions isn't that great either. Honestly the whole log/history aspect of Datomic sounds nice but never really used it other than for reverting stupid mistakes.
The #1 thing I love is the freedom of querying you get with Datomic. You insert your data in a way that makes sense for your data, and querying is pretty much a completely separate concern. For the most part you don't need to structure your schema around the querying capabilities of your database which I love. Say back in the day I liked Mongo because you could just insert whatever you wanted [0] but eventually you'd hit problems where you couldn't easily query your data (maybe it has changed over the years, no idea).
And the syntax is just a pleasure to work with. I'd love a version of Datomic that kept the same interface but dropped some of the more esoteric features in favor of performance.
Also I noticed some of the people reporting issues used the cloud version. Never used that so can't speak to that. On-prem is free and has all the features. As long as you don't redistribute it there's no problem.
[0] Yes in datomic you do have to have a schema. But it's pretty much a simple global list of possible attributes. If you need to add something later or make a change it's pretty straightforward.