I haven't made any Bold Statements™️ in at least half an hour, so I feel it's about time to do it again:
Rocket is the web server equivalent of what Rust is to programming languages.
It just clicked for me what
local_cache() does, and I had the same ("Oh, wow -- that's neat!") feeling as when I understood what
OsString is for. It's like you realize that the developers have run into the same things you yourself have, over and over, but they decided to fix it once and for all.
Disclaimer: I haven't used Gotham, actix-web and others.