It's similar in construction. Leo borrowed a few things like the grounded backplate, adjustable pole pieces, and of course the wide coil. However, it has one ceramic magnet that magnetized vertically, very different from Gibson's two horizontal alnico magenets.
The result isn't all that much like a P-90, it's more like a huge Strat pickup on steroids. It definitely sounds like Leo wound it, but it has more output, more harmonics and detail, and IMHO, is the most sensitive pickup to playing nuances I've ever used.
If that sounds appealing, go for it. If you just want a single coil version of your humbucker's tone without the honk of two coils, then a P-90 would be better. Either will give you more bass and treble. Neither will fit in a humbucker route, however.