Many years ago was trying to buy a cordless drill to in the USA and had a chat with the sales associate. He said I should ignore the claims made by one manufacturer about being the most powerful. I asked why and he said it just meant it had the highest capacity battery. There was very little difference between the two in terms of output.
This also make me think of Dyson and their "zero carbon emissions" claim. http://www.eevblog.com/2010/12/13/eevblog-132-delusional-dyson-marketing/
That's an amazing claim.....well it is.......but for a specific definition of carbon emissions.