I work for a small 2 people company, we recently switched to Infomaniak and there are a couple of things that need improvement, mainly the support for a better lite mode in Linux: they provide a WebDav connection but it’s a bit slow, even if workable.
On the positive side, we got also a custom domain for the mail box and website that was quite cheap and easy to set up. And the fact that’s all FOSS is great