Regards the error checking syntax the article may be right, but as far as I saw, the await addition to Rust went perfect: it became stable when the decision was made (also a state of the art memory model was created for async calls), and nobody had to use it (or even follow it) before that.
But those are rather just thread-safety annotations and not a memory-model
Pinning is of course part of the elegant solution. There are some great videos about it:
In practice, it's probably not going to matter all that much because the average web service does way more time-expensive things like disk IO or SQL queries. The more significant effect is that async-await being really really fast enables you to use it in more places. For example, if you have a tight computation loop where different aspects of the logic are meshed together in a hard-to-read way, now you could try detangling it into several async actors talking to each other to make it more readable, without utterly destroying the performance characteristics.