1. Scalability: One key difference between Heroku and Meteor Galaxy is how they handle scalability. Heroku offers horizontal scalability by allowing users to scale their web dynos or worker processes easily. On the other hand, Meteor Galaxy provides vertical scalability by enabling users to scale their containers vertically as needed, providing more resources to a single container.

2. Pricing Model: Another significant difference is the pricing model between Heroku and Meteor Galaxy. Heroku charges based on the resources consumed, such as dyno hours and add-ons, while Meteor Galaxy offers a flat rate based on the number of containers deployed. This difference in pricing models can affect the overall cost for users depending on their deployment needs.

3. Deployment Process: Heroku and Meteor Galaxy also differ in their deployment processes. Heroku offers a simple git push deployment method, making it easy to deploy applications quickly. In contrast, Meteor Galaxy uses a more structured deployment process involving building and shipping containers, providing more control over the deployment process but requiring more setup.

4. Add-Ons and Integrations: Heroku has a vast marketplace of add-ons and integrations to enhance the functionality of applications, offering a wide range of services from databases to monitoring tools. Meteor Galaxy, on the other hand, has a more limited selection of integrations, focusing more on providing a streamlined platform for deploying and managing Meteor applications.

5. Community and Support: Heroku has a larger community and extensive documentation available, making it easier for users to find support and resources for troubleshooting. Meteor Galaxy, being a more specialized platform for Meteor applications, has a smaller community but provides dedicated support for Meteor-specific issues and challenges.

6. Flexibility and Customization: Heroku offers more flexibility in terms of language support and customization, allowing users to deploy applications written in various programming languages. Meteor Galaxy, being tailored for Meteor applications, is more focused on providing a seamless deployment experience for Meteor projects, potentially limiting the flexibility for users with different tech stacks.

In Summary, Heroku and Meteor Galaxy differ in scalability options, pricing models, deployment processes, add-ons and integrations, community support, and flexibility for language support, catering to different needs and preferences of developers and businesses.