It is worth noting that Citus was acquired by Microsoft a few years ago (not a secret, but may not be obvious to everyone), and they have since shifted heavily towards the Azure side of the world.
Back when it happened we tried to buy their product and they were not sure if the Citus standalone product was even going to exist, and they refused to demo it even. Odd timing possibly, but it's a data point.
On the positive side of things, the shard rebalancing was not open source back then iirc, which made the open source version pretty useless. Now it seems to be open source: https://www.citusdata.com/product/comparison -- pretty cool.
I'd still be careful to bank on it as a Citus only customer or open source user.
There no longer is an enterprise version, what runs on Azure is the exact same Citus that you can run yourself. We even invested in Patroni, to make it easier for the community to self-host Citus with HA setups.
While we obviously want people using Citus on Azure, having Citus as a viable open-source choice is our path to achieving that. I wasn't part of the company when the acquisition happened so can't speak to that, but I can imagine how that could have made sales at the transition time unclear.
Personally I would also like to add, that the team is full of long term open-source contributors. We contribute both to PostgreSQL and projects around it (like pgbouncer). I understand and respect your reservation, but wanted to share my perspective on it.
Back when it happened we tried to buy their product and they were not sure if the Citus standalone product was even going to exist, and they refused to demo it even. Odd timing possibly, but it's a data point.
On the positive side of things, the shard rebalancing was not open source back then iirc, which made the open source version pretty useless. Now it seems to be open source: https://www.citusdata.com/product/comparison -- pretty cool.
I'd still be careful to bank on it as a Citus only customer or open source user.