Its hard to compare two different bikes (carb'd and fuel injected) because the properties of the air box and air flow control mechanisms are quite different. For example the new ZX-14's have an upper butterfly that limits air flow to the lower throttle blades where on a carb'd bike you typically have one set of blades, and an oriface the air is flowing through to pull the proper amount of fuel through mechanically. You will get the mechanical delay of the pressure in the float bowl responding to the change in air speed and drawing more fuel up the main jet. You also get a delay on the fuel injected system as the ECU needs to detect a change in air speed and apply the modified fuel requirements on the next fuel pulse, so on average you would lag one or two injector events at most. The nice thing with fuel injected bikes is that the ECU will actually detect a change in throttle position and add a little extra fuel the next fuel pulse, so that would in essence minimize your response time to one injector event later (think 4 injector events per 720 degrees crank shaft rotation) which is quite quick, being you have the mechanical delay of the air making its way through the blades. The fuel injection systems these days process data quite quickly, and the length of each fuel pulse fired is calculated using a base table look-up plus a compensation based on the dynamics of the engine sensors ( MAP, TPS, CLT, IAT, O2 sensor... )
I think if you had some sort of accel pump setup on a carb'd bike you would "help" get rid of that quick lean spike when you slam the gas open (with a proper air box and filter of course) otherwise you are at the mercy of the physical delay of the system.
PS: ( I'm one of the guys that helped tune the bike in this thread, that's why I jumped in. NOT trying to hijack your thread Aminosity :) )
1992 Honda CBR600 F2: K&N, Ported and Shaved head, SS Two Brothers Full System, Dynatech 2000 Standalone Ignition Control, Gutted, F3 Forks Front Wheel and Brakes. 86.7 RWHP @ 11,800 and 40.8 RWTQ @ 10,600 taken at 4500 ft.
2000 Honda CBR929RR: PCIIIUSB, Dynojet Wideband Commander, Dynojet Ignition Controller, Dynojet quick shifter, Jardine Slip-On exhaust. 125.6 RWHP @ 10,400 and 66.9 RWTQ @ 9,200 taken at 4500 ft.
1981 Yamaha YZ465: 0.040" overbore, Forged Wiseco 10.5:1 CR, Mild exhaust port work, 0.010" Shim under base gasket for changed port timing, Full DG Exhaust, Renthal bars, FOX grips, RK chain and rear sprocket.