We do. We're a non-profit, and a few years ago we went cloud-provider hunting. Microsoft was willing to be generous with us in a way that Amazon was not. Not only in terms of non-profit friendly pricing, but also in terms of incidentals -- trainings, related services/pricing, and so on. Amazon offered no concessions at all, so it was kind of a no-brainer for our CTO and board.

So everything we host is Azure. We are a relatively small outfit, but a fair chunk of our 'stuff' is customer-facing. We haven't had any negative experiences yet at all and it's been a few years now.