Slack has been around for a long time, and it's an industry leader. Of course, Salesforce owns Slack now and is starting to integrate into it. I have attended Slack conferences and met with product and support managers. They're an excellent organization. Choosing Slack depends on the organization's size, so you need to plan your deployment and make sure you put some controls and standards in place and not just turn it on. If you're a Slack shop, you will have to have something like a Zoom or Microsoft Teams platform for when you need to do video conferencing internally or externally. Many shops have both products, but they use Slack for collaboration, chat, and so on, and use Teams for video and audio conferences. At the end of the day, Slack is missing those capabilities, so either you're going to be a Slack/Zoom shop or you're going to be a Microsoft Teams shop. I rate Slack an eight out of ten.