We changed the architecture quite a bit during the beta period to address feedback like this. With what's available today you don't need to run all your steps in a container. You _can_ take advantage of containers, but you don't _need_ to. We host Linux, Windows and macOS virtual machines for you to use and you can just define a commands to run on those machines.

We're working on artifact caching between runs now, which I think will also help some of the speed issues that you're referring to.

We really appreciate the feedback; if you do get around to trying it again, I'd love to know more about what we could improve.