You can't compare them to humbuckers. What they are is a P-90 type pickup that is built to fit in a humbucker rout.
IMO they don't sound as good as a real P-90. Either that or they don't imitate it very well. A normal P-90 has +/- 10k turns of AWG42 wire on a 1/4" tall bobbin. That's impossible to fit in a HB rout.
To compensate they change the shape of the coil. Therefore it's difficult to imitate a P-90 tone.
A good comparison of what I mean would be a Jazzmaster pickup vs. a Strat.
I've never tried the p-94 but I expect it's a great sounding pickup.
When I needed to go from humbuckers to single coils in my guitar I ended up getting Fralin p-92s. I have been very happy with them. They're 2 coils configured like a p-bass pickup so they're hum cancelling without giving up the single coil sparkle. They're voiced to sound like p-90s but I'd say they're a little brighter. They'll still drive your amp nicely.