Welcome to you both..
"Tuning" is re-writing the factory calibration for more power and usually better fuel economy. "Deleting" is removing federal mandated emissions that really is against the law, but some companies do offer a way to do it.
Wait? Are you saying that I think Sofa King doesn't have "morals" and I prefer GDE? Then you are WAY off base. My comment wasn't directed at neither company. In fact, I don't have an opinion on either as I've not used either personally.
It's the moral aspect... if you modify the write counter to help the consumer and in turn not void the manufactures warranty, what does that say about your company?
And yes, the dealer can't likely tell if the truck has been tuned, but I promise you the engineers that developed the factory...
Welcome!
I'll let the guys chime in here on some questions you have.... as far as warranty, tuning it will likely void it IF something happen. But, the increase in power is nice.