Can you please elaborate on Deno language server being better over tss? Does it have smaller latency, does it start faster? Is it a drop-in replacement or some features are missing?
It is a drop-in replacement. Deno has a Node compatibility mode [0] which — besides the execution — also applies to LSP, so the Node-specific idioms are processed correctly.
It is not cosmically faster than tsserver, but some — including myself — do prefer it. I wouldn't recommend to change anything if you are busy — but maybe take a glance when in the mood for checking out new things.