Explicit vs implicit dependencies (useEffect vs Signal.Computed/effect) and the fact that signals in contrast to useState can be used outside of react context which I assume is a good thing.
I personally mostly prefer more explicit handling of "observable values" where function signatures show which signals/observables are used inside them.
They’re very similar, and you can definitely squint right to see them as fundamentally the same concept… if while squinting you also see a React component itself as a reactive effect. Which is all technically correct (the best kind), but generally not what people mean when they’re talking about signals in practical terms.
Signals are fine grained reactivity. React is coarse grained reactivity. Legend-state adds signals to React and I'd recommend it over Redux/zustand which we used to use.
I personally mostly prefer more explicit handling of "observable values" where function signatures show which signals/observables are used inside them.