If you're from outside of the US coastal cities, specially from countries in South America, Asia where currency can be more than 3 times devalued, than it quickly starts to become a big deal.Apart from that, we are currently offloading a whole lot of out IPs and knowledge into the care of companies we don't really know and where we don't hold any real stakes.I tried Matter Most first and I really wanted to like it.
For small installations I really prefer to have Postgre SQL.
Mongo DB is competent, but for medium to big installations, and I will show you why below.
For most companies, the conversation history is not so important and even the free-tier will be more than enough.
Cost is less relevant depending on your context, and there are many different uses for group chats.
In my previous post I forgot to mention minimal firewall and SSL configuration, but you can check it here.
One of the most difficult pieces to move away from is Slack.
Some packages do have jasmine tests, but the majority is lacking.
This is one example I picked randomly, out of the few test files I found: Really?
I could pay Slack already if I didn't care, so I would not just pay an alternative and not have full-control (including the ability to tweak and improve the entire code base). It's feature set also rivals Slack, it's good looking enough. Now, I don't have anything against Meteor and I really think a Slack-clone is exactly the kind of use case where you could use Meteor to its full potential.
Technically I really think it's a downside to be forced to use Mongodb (Meteor requires Mongo).
If you want permission control for that you must use their "Enterprise" offering and pay USD 20/year per user.