Another way to describe what a Blackbear tune does is that it 'wakes up' the vehicle.
*Throttle response improves -
*shift points are tuned for better drivability (the factory tune prioritizes economy),
*shifts are quicker with less TCC slip ...
Other tuners besides BlackBear SHOULD be able to accomplish the above.
*Electronic-signal-throttle vehicles NEVER open or close the throttle as quickly as your foot can - unless you have your ecm tuned.
*GM OE transmission shift pattern not only prioritizes economy, it either encourages conservative driving, punishes enthusiastic driving, or both.
If you're a hypermiler, you might even ask your tuner to prioritize MpGs EVEN more.
The rest of us likely would want something less lazy than GM provides, though.
Since we have TWO shift tables, how do you want the 2nd one?
Since I'll likely NEVER tow anything, my Tow / Haul mode is more like a 'try as best you can to chase that TrailBlazer SS' mode,
which is why my normal mode prioritizes neither MpGs, nor lazy driving - it simply protects the 4L60E as best as possible.
Maybe you want your Tow / Haul mode to entirely avoid 6th, or 5th & 6th? You'll never get what you want if you don't ask.
*GM OE TCC behavior for '1500' type vehicles prioritizes NVH over durability/longevity.
Your 3500 may not have this particular problem, but most of us do ...