I'm currently using Netlify CMS on my Gatsby site for the blog bit. Any reason I should switch to this?
Tina is also designed so that you can create the editing experience that your customers/clients/coworkers need. Instead of a one-size-fits-all solution, you can give them something that is tailored to their needs.
As well, at the moment Tina only works with git (similar to NetlifyCMS) but we are working on other data source plugins as well (think Contentful, Headless Wordpress, etc).