How does the AD 4G 200 stack up?
In what regard, fuel flow? All of the big name pumps flow close to what they claim. I believe Power Driven diesel did a few tests on lift pumps in regards to claimed flow/pressure.
IMO nothing can touch Fuelab in terms of big power flow-rate. For example, my Prodigy was hand tested and flowed with mineral oil before it left their company and that test sheet was included. My Prodigy is rated at 200gph @ 20psi. My actual pump flows ~225gph @ 10psi and closer to 235-240gph at 0psi.
AD/FASS claiming they remove air from the fuel is a gimmick IMO simply because gerotor pumps introduce turbulence into the fuel flow where as vane pumps (like the Fuelab) do not. The other benefits you gain from something like a Fuelab is the ability to run at a reduced speed when not in use reducing noise and increasing the lifespan of the pump.