Rust - What makes Rust Programming language special?

I think that the following features in Rust will make it special.

1. Package manager.
2. Functional style programming.
3. No exception.
4. No garbage collector.
5. Compile time error detection for multi-threading programming.

However, I think that the following features make hard to master Rust programming language.
1. Ownership, borrower and move semantic. (but if somebody has a strong C++ programming experience, this is easy to catch up)
2. Lifetime indicator.