Alright here's the deal...
It's very simple.
You only want to consider dry and direct port and I'll explain it to you the same way Kurt and Wady explained it to me (former technician and VP/GM for NOS before they were bought out).
Here's why:
Nitrous Oxide when bottled is a pressurized gas in liquid form, once introduced to oxygen it rapidly expands back into a gas at the rate of 900-1000 psi (or whatever pressure you run typically 900-1000 is optimal).
Now look at house who's exterior is covered in stucco and note 2 things: rough texture and surface area.
If you were to hold a nitrous bottle and spray the side of your house at 900-1000 psi - nitrous doesn't care, it flows hard with
zero resistance.
Now take a water hose ( regardless of what type of attachment is on it) and spray the side of your house.
The water obviously sticks to the side of the house right? Notice how the texture immediately slows down the speed of the water hitting it - regardless of how fast it comes out.
Same thing with a wet kit.
When you measure the location from the nozzle in the intake to the number one cylinder (which is where 75-80% of the nitrous goes on a single fogger set-up) it averages about 3 feet (not counting surface area). When you have a nitrous racing at 900-1000 psi versus fuel at 45 psi (which is a liquid that sticks to and lines in the inside of the plenum) who do you think is gonna win?
Nitrous obviously. This is the number 1 reason for the "nitrous nightmares" you hear of.
The best way to combat this is to augment fuel supply by spiking the pressure via the oem fuel system.
Travel from the fuel injector to the head - about 1 inch (a heck of a lot shorter than 3 feet).
That being said you get lop-sided loads with a single fogger kit and the other cylinders when using a dry kit go a little richer (still a million times better that a single fogger wet).
The best way hands down is a direct port. Each cylinder gets a perfect blend (depending on the tuner of course). Not to mention it feels 100x better.
the only time single fogger wet kits should be used in a hat application (carb set-up) or in a forced induction scenario.
personally you can't beat a direct port. SR's love them.
Stay fresh...