I revisited this and directly compared some of the pickups in question.
First: P90 tone...what do you mean? Do you mean something that actually acts like a P90? Have you used P90s extensively? If you haven't, you probably don't know what that is. They have this high end roll off thing some people love, I h8 it with a passion as it kills pick attack dead. Sounds like a strat pickup or a PAF with the tone rolled all the way down even when it's wide open. Gets exponentially worse as you add wire, so if you overwind one above 8k, the high end takes a dive into hell. If you never pick fast, ok, but if you do, you will hate it with a passion.
What people who haven't used them tend to mean is, big fat loud single coil. So which you mean makes a difference.
Kinman Big 9-0: Sounds like a P90 insofar as it's hot, and the high end is compressed and rolled off, albeit not quite as much as a 90. The more I play it, the more I hate it. It has a weird high end that is muted, overwhelming mids like a cocked wah, and not in a good way. Sounds good on low chords and some power chords, h8 it for leads. I can get similar sounds if I take an Injector bridge and roll the tone way down, but the injector never sounds or responds as bad as the Big 9-0. If you've really extensively used overwound P90 bridges for real, you might like it as it has some of those qualities. They are qualities I personally hate though.
Injector Bridge can do the bright strat thing with the tone wide open, but responds very well to a .0015uf cap rolled down. Becomes fatter but not weird like the Kinman. Sounds like Blackmore with that setup and the tone rolled off, but I'd compare it more to a tight PAF with that done than a P90, unless your definition of P90 is the second one I use above.
Fast Track 1: This is the 2nd definition I use above in spades. Big, fat, loud single coil. No high end weirdness of a real P90 or the Kinman. Like the injector, responds well to a.0015uf cap on the tone control, but wide open it's perfectly usable. Bright highs and big, tight, but not boomy, low end. I really like this in the bridge of a strat, it sounds 'right'. Bright enough to mix with the singles, enough bass to not sound thin, fattens up nicely without losing all articulation as the tone is rolled back. This would be what I'd point someone to if they wanted a really huge single coil sound in the bridge, like all the good qualities of a P90 with none of the high end weirdness-baggage. Add: Plays nice with 250k pots.
Chopper. This is a PAF sound, I don't care what DiMarzio says. I compared it to at least 30 different PAFs in the bridge of strats and it falls right into that camp, and it's one of the best available as well, really sounds great. Sounds nothing like a P90. Fatter, no high end roll off or compression. I love this pickup in the bridge of a strat to. Add: Works better with 500k pots.
Also RE the chopper and fast track 1: You do NOT have to split them in position 2 to get good quack with the middle pickup. With full sized humbuckers, you really do, and you need to use the bridge coil, which often means flipping the magnet. FT1 and chopper have a tighter magnetic field and do not need splitting for a correct strat position 2 tone.
