Unfortunately when you inevitably make changes to your CF config, `terraform plan` doesn't help because it's likely you changed something inside the `template_body` and Terraform just knows the string has changed and doesn't tell you what part of the config changed. Parameterising as much as you can helps.
The primary advantage Cloudformation has for myself is a lack of need to manage the state that Terraform spends so much effort upon. In fact, Cloudformation does this fairly opaquely but was much more obvious when I tried to deploy a CF stack when S3 was down a while ago - being able to use an alternate state file location would have been handy then.