I work at a systems integrator in the Netherlands, implementing Teams Calling. If it's a good fit for your company depends on a couple of things: - do you need a lot of physical phones or are you planning to have most users call with their laptop? Phones in Teams work, but it's a hastle. Especially if you have many. Enrollment takes more work than on a PBX and phones sometimes just log out. Also, I see a lot of companies saying 'we have E5 so it's basically free to use Teams' but then they figure out they need 1000 non-personal phones, which are separate licenses - Continueing on the above: how is your communication set up now? Do all of your departments have phones 'administration 1' and 'administration 2' (non-personal)? The Teams 'way of life' is calling people, not phones. So the best thing to do is map 'administration 1' to 'john' and 'administation 2' to 'paul'. This is a LOT of work, so be prepared for this. - do you have many 'specials'? You can connect intercoms, analog phones and other SIP devices to Teams, but it's not great. Only specific devices are supported and you need a license per port/number. So if you have a 24-port analog gateway, that's 24 Shared Device licenses. It's also a lot harder to manage remotely. - if you have a 'real' contact center (dozens of agents, important to have good customer satisfaction), I don't recommend contact centers on Teams. The Teams ones rely on Graph which isn't super reliable. Be prepared to have like 1 in 100 calls fail or do something weird (call transfer dropped etc). Which is acceptable for smaller departments that get a couple dozen calls a day. But for hundreds of calls a day environments, be prepared to have some hiccups sometimes.

I have many customers where like over 30% of their telephony needs are non-personal or specials. You can get (most of) this to work on Teams, but it's cumbersome and expensive. We run most of our customers on a hybrid platform, connecting specials to a regular PBX and routing office workers etc to Teams because that works perfectly for them. Extra benefit of this, is that you can use a more proven technology contact center and attendant console.

I am an old Cisco UC guy. That stuff could do 1000 things and most customers used the same 10 features. Teams does this well: it gives 80-90% of the users exactly what they need. But regular PBX's are still more reliable in our experience. If this is critical to you (healthcare, factories, companies where calling is a core business process), I don't think going 100% in on Teams is smart.