A gage is fine for tuning a steady condition. By this I mean say you want to know how an adjustment effected the AFR at idle. Or, driving steady on the interstate 65 mph. Or even pedal to the floor, from last shift through the lights.

For all that, a gage is good.

But if you want to know what happens as the throttle moves, or the car starts to go up a hill, or some more detail, then a logging with other info is a really needed. That way you can see the relationship with rpm at a minimum, and tps, manifold vac, etc if you want. For logging the LM2 like Mark mentioned, or a gage with the pocket logger are pretty good consumer grade options.

So all depends on what you mean by tuning and how deep in you think you're going to get. Innovate's stuff is fast, and it has error codes, and can be calibrated. OTH logging software and hardware setups are not the most user friendly.