But please don't let me get in the way of a good anti-establishment rant...
Most people didn't really know the difference, and many companies didn't publicise the last one because (a) people are dumb and might think 200 watt nozzle suction is worse than 1500watt engine power, and (b) because it'd show their machines are crap.
Example - dysons when I was selling them had lower engine power than, say, hoover(1200 vs 2000 watts iirc), but had comparable or higher suction power because the suction didn't need to get through the walls of a bag & a bunch of filters.
End my 2 cents.
The number of computer scientists in a room is inversely proportional to the number of bugs in their code.