For running application tests it's well suited. H2 [Database Engine] can replace the real-world database solution for them easily and removes the requirement to set up a a separate database instance just for running unit tests. For using in actual production application one needs to consider scale. H2 is suitable if application runs in single instance and database is located in same machine as a file where that application runs. This means the application shouldn't have a large user base. However it's easy to switch to an actual MySQL instance if the need arises, it's most likely only a configuration change and doesn't require new code.
It's a great tool when building the software, the ability to add SQL and No-SQL databases. Very convenient to write the queries and generate the filtered data we require. Gives the ability to export, import databases of various formats and generate reports from them. It might not be suitable if you want the data to be seen in a visualized manner
It crashes CONSTANTLY. If you have more than one connection tab open and close one of them, it crashes. If you just have it open in the background, it randomly crashes. If you're using it, it randomly crashes. When you try to send a crash report, the CRASH REPORTER CRASHES.
Can be a bit slow.
No way that I'm aware of to query multiple databases in the same query.
It's open-source and very convenient to work with. I can easily import any database I want using a data dump and runt the queries on them to derive the data insights on the data. I might want to use Excel to visualize that, that might be one of the disadvantages.
While both can run as an in-memory database, H2 Database Engine was just so much easier for us to use since we primarily use the Java stack and H2 Database Engine is also built with Java.
MySQL Workbench is a wonderful tool, but the routine editing of existing data is note nearly as straightforward as it is in Sequel Pro. The ability to sort a data view with a single click makes Sequel Pro my definite choice. phpMyAdmin is pretty ubiquitous, but the routine editing of existing data is much more cumbersome than it is in Sequel Pro.