V8 is ringing endorsement for V8. It is just a well-designed JavaScript virtual machine. It's performant because it compiles JavaScript to native code and uses generational garbase collection.
Somebody below said just the opposite. Personally, I find V8 really nice to read and work with.
Which part of it do you not like?
Just so we are on the same page. I am refering to the V8 codec not the Javascript engine.