Tangential, but which of the 7 ended up being the best experience?

It's a tossup between Dart and Bun: Dart has better language features but Bun has better APIs. Since Bun is first and foremost a Javascript runtime, it inherits its annoyances and issues, like the complete lack of pattern matching, or switch expressions at all, or decent enums, etc. That said, Bun includes SQLite support and encryption out of the box, whereas Dart is heavily compartmentalised (https://pub.dev/publishers/dart.dev/packages). Imagine if, in Bun, importing "node:crypto" meant needing a "node:crypto" npm dependency. Dart ekes out the win though, I think.