I like this statement in that read

"Multiple turbos imply more power. Power is, in part, a function of efficiencies. All other things equal, a big turbo is more efficient than a small one."

I thought the more turbos the better. Look at the Bugatti Veyron, no, not the one in the water from the cell-phone distracted driver. The ones on the road.

Or in my line of work with Volvos, the 2003-2005XC-90 has an inline 6 cylinder with 2.9l of displacement and 2 turbos with a power output of 286 hp. Seriously de-tuned to comply with Volvo's hardon, errrr.. I mean, commitment to safety. They feel slower is safer.