Queues are not magic. If they're unbounded you're in for a world of pain as load increases.

Interesting approach to provide more fairness to client requests.

Indeed, in most case you don't need the extra complexity. Also interesting is showing that even if the application has to scale rapidly you still got quite some time to plan the transition to something else. It makes Postgres a sane default choice.

Interesting way to approximate how loaded a system is.

Neat way to see how several queuing strategies behave. Picking the right one for your system is important.