Re: P-90 vs. '59 in Hamer Mahogany?
Welcome to the forum brother. It's a real hard thing to describe for me. P90's are really cool old-school single coil with a lot of mids. They are real "fat" sounding pickups. Take a strat single coil, and give it a massive dose of Sterioids and you get P90's. Full, rich and they just sing to me. I favor the P90 tone over humbuckers for the most part. You can get them with one being reverse wound, reverse polarity for a noise cancelling effect when both are selected. I find that there is a little bit of that "strat quack" when both are selected. But it's not a big thing because the p90s are usually a bit farther apart than two strat pups, so less quack, but I still hear it.
That being said, the 59 humbucker is probably the best selling Duncan pickup bcause it has a nice tight bass response and a full tone that is very much noiseless.
To stereotype, P90's can really do the blues/rock thing very very well. Country too. The 59 model is probably more associated with the old school rock tone. but, in the right hands, the 59 can probably do any type music you'd want to play.
A third option, is that if you get the 59 version, you can always put some Phat Cats into it later. The PC's are true P90's in a humbucker package. You can drop them in for the P90 tone in a humbucker guitar. More flexible option.
Also, keep in mind, there are a LOT more humbucker replacement options than there are P90 options. Just another factor.