I think he has been reading too many ads and listening to all the guys that don't know anything about tuning posting that you need one to tune....
IF, you have a chip that can be driven closed loop by a wb, then you might be able to justify having one, but, if you have a street car, don't bet on going any faster. Also, it only sets the a/f to what you typed in and does not give you the flexibility to vary a/f versus rpm and load. AND, you still have to determine what is the optimum a/f....and how do you do that?
Just like with a factory narrow band...lean as possible without detonation plus a desired safety factor.
I think some have been led to believe that there is something magical about a wb and they do not have to know how to tune because it does it for them or they think because Joe runs 10.6-1 and he goes high nines...that is the number they should dial in to run 11.8 times.
I use the SD chips which can be driven by a wb, but after twice having the wb stop working when I was wot, I decided to set the car up and then go open loop so I did not go from a 10.8 to a 14.7 in the blink of my eye.
Then we complicate things by having an alky set up...alky affects the a/f so if you spray twice as much alky with your dual nozzle set up as your buddy with a single nozzle set up, and set your a/f's the same because you believe in magic numbers one of you may have an awakening. Straight methanol may make the most power at an a/f of 4.2 whereas straight gas may make the most power at 10.6 in blown situations. So what is the magic number if you are spraying a mix? (there is something to be said for using lambda)
You still have to tune the car!