A bit long, but real world facts.
The changes you made from the V&H to the new slip ons is one that we have done. A new map is needed. Myself wish that a simple plug and play setting or map, that is a one size fits all is the fix. But in the real world it does not work that way. Even guys that sell the PC with a "tuned" map are only fooling the customers and providing a map that is " ballpark" ready nothing more or less. I have had WAAAAYYYY too many bikes come in with the pc and free map that they installed have issues,... and once tuned they are smiling.
I know that many think that a quick adjustment system is really all you need.
If that was the case there would be no need to a have over a 1000 cells ( stock ECM set up) to tune. When some one tells me that it is spot on and it correct I always smile and nod. What is the spot on tune being compared to?? a stock bike well they are not the best, so the new parts with increase in power and a free map?? Its worth just what you paid for it.
For some that is all fine and well. Want the bike to run flawless across the entire RPM range, seamless from each and every throttle position?? That means a custom map.
What is funny or strange not sure which.. Is that the car side of performance, as they know 100% for sure that the mods they make to a EFI engine WILL require a custom tune. They know that it will run some where in the 700-1000 dollar range and do not complain if there one size fits all map does not work as well as it could.
I had my own LS6 engine tuned in my sand rail. Engine was the basic set up with a GM hot cam with the GM download. It ran fine, however I knew that there was more power to be had. I picked up a huge gain , I went from 338 HP and 342 TQ to 380 HP and 360 TQ.
On bikes we have tuned the odd box stock bike and seen a fair gain, not anything that I think you would say WOW about, however on the stage 1 stuff tuned vs a plug and play deal 10/10 gain is the norm. If I broke it down into a % the gains are huge 15% ++ IS THE NORM. Not cheap , that I will agree on however end of the day, if you want to play with these EFI systems it will cost you.
I have made the deal with many a customer on a money back deal if they could not honestly feel the increase in power, ( cooler running, t-response, MPG, power, etc) I would give them all of there money back. I have never had to refund 1 dollar on custom maps.
Everyone that is skeptical always tells me hoe much better the bike runs every where in the RPM range. The bottom line is that once you ride a correctly tuned EFI bike you will know where the money went and smile, as the end result is so much better.
Again it may not be for all, some are happy just that way it is, I have many a customer that love the stock power they have. Different strokes for different folks.