It certainly can be, depending on what you compare it against and how you measure.

It is based on V8 which in many (caveat: far from all) benchmarks comes out as the fastest JS engine, so by that definition in the realm of JS powered components it is pretty quick.

node.js solutions will often perform better than common configurations of other options too - Apache+PHP to pick one example out of the air. Then again, depending on the code other configurations of PHP might outperform Node.

Surprisingly yes. It has billions of dollars or optimizations and research in it over the years and can really fly. Of course you can write slow node code just like you can in any language, but a single well-written node instance can handle a lot of traffic.

Billions of dollars? I have no beef with Node, but that seems like a lot. Could you elaborate?