@mushroom
I recall being taught (school-level physics) that most mechanical devices were, at best 30% efficient, in thermodynamics terms. So 63% efficiency (the converse of "37% waste, as you said it) seems pretty darned impressive, to me.
You mentioned a few single-figure-percent additional downstream losses so, for comparison, what is the energy efficiency of good old steam engines?
Btw, you're right about the pollution merely being relocated, which is the same problem we stand to have with electric cars. However, moving the smuts elsewhere was the whole point - get it out of the cities and stick it where only handfuls of houses get the soot landing on their car/washing line etc.
Incidentally, China's coal-fired station pollution is, technically our pollution if, as I suspect, they are being put in place to drive all the factories making our consumer products. (Cough, hack, wheeze).