Thinking is quite a bit faster. I have caught myself altering phrases mid-pronouncing because i was thinking more about it while talking and thought of a better thing to say. In practice that tend to produce garbled words.

You can probably notice similar things yourself if you pay attention, and that's the closest to evidence we can get at the moment due to lack of telepathy or equivalent technology to actually measure these things reliably.

As far as Neuralink goes, assuming it won't be made in the stupidest way possible (reading commands spoken by imaginary voice inside your head), it could be quite a bit faster than hands or speech.