Slack for sure. All the employees are going to be pissed off for months and lose a lot of productivity while they learn the new UI. Git only impacts developers

Slack for sure. All the employees are going to be pissed off for months and lose a lot of productivity while they learn the new UI. Git only impacts developers, a smaller user base, who can figure out how to use a new website. That being said. They are both easy switch. Just need to update the URL to the new tool.