Deixo-te aqui um treixo de um artigo que explica relativamente bem a "cena":
The DC (direct current) resistance of a guitar pickup tells you how much the wire coil in the pickup resists electron flow through the system. Knowing the resistance (measured in kiloOhms or kΩ) only tells you one tiny bit about a pickup and it's potential performance and sound.
In addition to DC resistance, the sound and performance of a pickup is related to its Inductance (in henries or H) , Voltage output (or output to input ratio) at normal playing levels (often reported as the "power" or "output" of a pickup), capacitance (in farads or F), overall frequency response (a curve of voltage output at differing frequencies), frequency of peak output(s) (often considered the "resonance" of the pickup); as well as all of the materials used in the construction of the pickup and their composition (like using brass vs. nickel steel for the frame of a humbucker or AlNiCo vs. ceramic magnets, for examples).
DC Resistance (DCR) is easy to measure and ROUGHLY correlates to pickup output and ROUGHLY correlates to the frequency range of the pickup. In general, a traditionally made humbucker pickup, for instance, may have a DCR of 9 kΩ. By itself, this tells you almost nothing. Comparing this pickup to a similarly built humbucker (same materials and construction technique, but with a greater number of coil windings) that has a DCR of 10.5 kΩ, however, you would EXPECT the 10.5 kΩ pickup to have a bit higher output as it hits your amplifier and you would EXPECT that it probably will have a little less (a teeny bit less) treble response than the 9 kΩ pickup.
That being said and explained, though, if you are comparing one pickup with another and they have a number of differences in materials and construction between them and THEN you compare the DCR, that DCR comparison means very little, indeed.
DCR is reported by most pickup manufacturers because it is easy to measure and resort and because so many guitar players over the history of electric guitars have come to believe that DC Resistance has some magically important meaning.