the gauge is for a wide band sensor to read the afr that v tune cant read. its a good idea if you want a complete tune,and all you can do is strap a laptop on your bike and read 30-80 kpa. areas.
alot of guys get a "good enough" tune out of a v tuning. and are happy. I agree it is not a great way to tune,but has a lot more adjustment than a fuel pak.
I only tell it like I see it. I have never tuned a bike with a RB pipe,that I just went WOW that pipe really made a diff. Now I have tuned the same motor with RB and swapped to another pipe and retuned and picked up hp/tq. they are a single wall pipe and the chrome does suk.they all turn colors at the collector. then if you buy there heat sheilds to cover it ,well they are a joke.
the only advantage I see with RB pipe over some of the others that out perform them is they are light. very light,wonder why?
the black ones I have tuned held up better than the chrome,but the black gets dull looking pretty quick.
a fuel pak can benefit a stage 1, if you can get a handle on how to tune it.
remember most people dont miss what they never had.
and most wont admit that something they own or use,is a POS.
When I say I take them off ,and then tune them, I am serious.
any dyno tuner will laugh and tell you ....your wasting your time and money wanting them to dyno tune a bike with a fuel pak on it.
do your own thing man that is what makes this country great.

but you could pick up a pro pipe for 380.00 and a tts for 375-400.00.about what your gonna spent on the RB.
you will have better luck throwing tts canned maps at it than fuel pak maps....since it seems you dont want to have it dyno tuned.:spank:....