Which ones are really better?
I dont mind getting a resistor box for Peak if they are really better.
I've heard it both ways.

 

from what I've read, saturated injectors have a relatively slow ramp-up, that is, the time it takes for the voltage to fully rise and cause the injector to open. I say relatively slow, but remember this is all still happening in a matter of milliseconds. Typically, saturated injectors are fine if you're running lower volume.

Peak-and-hold injectors have a little different voltage profile. They are subjected to a MUCH higher voltage than nominal, causing the voltage to climb very rapidly before the "hold" phase where it is allowed to settle back to a nominal voltage until the scheduled closing time. It's like the difference of opening a door and kicking it down. So obviously, the advantage of peak-and-hold injectors is if you're running a larger injector and are suffering idle quality issues because a saturated injector can't open and close fast enough at the lower duty cycles to really meter out such a small amount of fuel.

So... depending on your application, you can choose what's best.