I own a Dynojet248h dynomomiter with a wide band O2 sencor. I use it to tune all sorts of cars most every day.
To answer your question, yes it will help you tune your car.
I would go to a dyno shop in your area that has a wide band O2 and tune it there, then use your gauge like a warning light. I have seen alot of diferent gauges. Some are acurate some are not all have the tendency to make the driver a nervous wreck.
The O2 sencor that I use in my dyno cost $400, just the sencor.
You will get what you pay for
Tune tip: Most NA cars run best around 13.2/1AF.
Your AF gauge will read this as rich.