Anecdotally I know of one company which is also in the same boat and generally regrets their usage of Datomic and is trying to move away from it last I talked with them. However, there's also people on HN like dustingetz who have had a great time with Datomic and use it as a core component of their product.

I just wish Cognitect would allow people to run public benchmarks of Datomic to make it easier to evaluate its tradeoffs.