I have one in the neck of a les paul.
The pickup itself does contain a decent P90 sound, and a good HB sound and a passable single coil tone.
BUT
yup you saw that comming I bet, you can't get all three at the same time. To get the best single coil sound you need the pickup close to the strings, so close that the P90 sounds really bad. The P90 needs it quite a distance away which completely ruins the single coil tone. So you have to compromise.
Personally I think the magenets for the blade pickup might be too weak in comparision to the two whacking great magenets I'm guessing are stuck either side of the P90 bobbin.
I have mine set up so I get a good P90 sound and still have a good HB tone. I'm not to fussed about the single coil but it sounds ok to me, not great, not as good as the P90, but ok.