Sure it's better ! If you can have some well canalysed and not turbulent air at engine inlet, this one will be more efficient. It's the same effect as with bypass setups.
A friend have this effect few weeks ago with an electric ducted fan on E-flite F-86 : This is the same setup as on Habu, but on the F-86 it is all ducted from nose to tail cone. It run more quieter with a very different sound and with more efficiency. Why it should be different with kero turbines ?
