I used it, but since people don't like to take me/my word for it, I'll just post some 'objective' facts about it.
When you split it, to the weakest coil, the sound gets very thin (subj.) but the output drops down like crazy (obj). With the other coil on, the output drop is there, but less than with the other coil (obj). when you put those 2 coils in series, the 2 signals are summed up. the strongest coil is the carrierwave, the weak coil is the modulation-wave (but weak, since the coil is weak).
the tone you hear when the pickup is in series, will, thus, be somewhat like the tone when split. but a bit noisier (obj) and its got a bit less 'balls' (subj).
everywhere were it's 'obj' its an objective observation, and subj. is subjective, aka: my opinion.