> Using binstubs rather than "bundle exec" can be a good deal faster.

Absolutely, which is why we switched to them with Rails. It is a tough problem, though, and given Ruby's constraints. In my testing, it's the startup time that's the issue, not Thor, which is because `bundle exec` has to re-start the interpreter multiple times, and binstubs don't. Anyway.

> I just hope that performance is a core design consideration for Cargo

Rust people already feel the pain of very long rustc compiles, so while I'm not sure that it's an overriding concern, given the Rust world's concern with performance in general, I expect it to be way better. Ruby has always kinda thrown performance to the wolves.

> I legitimately just want to make sure Cargo comes out awesome.

We all do. And I'll admit to being a bit sensitive to 'lol bundler,' which I feel is often said without fully understanding the problem space, which is admittedly large. Not that you are doing that, but I have seen similar comments elsewhere. Once you explain the details, it's pretty clear why Bundler does what it does.

Anyway, yes: let's make Cargo 1.0 and Rust 1.0 super awesome! I'm really excited that we're taking this step forward. It's a huge day for Rust.