A properly setup sequential twin turbo system is what the above person was probably talking about. Instead of having two turbos running at the same time you have a smaller turbo for the lower spool and bigger for the higher end.
As far as twin charging it's like anything else. You can do it correctly and make good power.
There are cars that make crazy power twin charged. Obviously the setups are different but still they are twincharged. I just don't think people take the time to fine tune or work the kinks out and quit.
This is not a 3800 obviously but it's twincharged:
Zenvo Automotive
1104 BHP and 1430 nm of torque isn't too bad. lol
