How this category actually works

The rest of this site answers "which one should I buy?". This section answers the questions underneath that — the ones that decide whether a buying guide is worth reading at all.

Most of them come down to the same problem. This category publishes an enormous number of figures and almost none of them are comparable. Suction is quoted in three incompatible units, runtime is measured in whichever configuration flatters the machine, filtration is claimed as a percentage with no test standard attached, and performance is compared against "the leading competitor" who is never named. A reader trying to choose between two vacuums is being handed a spreadsheet of numbers that cannot be put side by side.

So these posts do the unglamorous work of sorting the signal from the theater: which figures genuinely compare across brands, which qualifiers change what a number means, what a manufacturer telling you something inconvenient is worth, and where the cheapest possible answer turns out to be the correct one. They are the reasoning behind our method, written out for anyone who wants to check the working rather than take a ranking on trust.