I purchased the Trifecta tune during the 2015 black Friday sale. Besides the desire for a power increase, my primary concerns with a tune were loss of drivability, more frequent regens, and loss of fuel milage. That being said, the Trifecta tune has met or exceeded my expectations on all fronts. The tune is truly impressive in its seamless integration into the engine and transmission controls. If you had never driven a stock CTD, you would have no idea it was tuned.
I'll touch on a couple of your interest, and my observations;
I've gotten accustomed to rolling on the throttle to help decrease the initial turbo lag/torque managment before the tune was installed, so the difference there wasn't huge. I would say its better than before, but not gone.
As far as drivability, the car is a just a quicker, smoother version of its previous self. It hasn't surged, bucked, or lunged once.
I didn't have confidence in the ability of a tuner to improve upon the factory transmission controls. But they did, it's nothing dramatic, just noticeably smoother.
I wasn't interested in different tune levels. I wanted as much HP/Tq that was possible without negatively affecting stock fuel mileage and regen frequency. The tune has delivered on both.
By chance, I installed the tune less than 10 miles before a regen. Close enough for me to call it a stock tune regen. The distance on that one was 802 miles. The car just completed another regen yesterday. This one came in at 794 miles, pretty impressive for the amount of WOT/heavy acceleration i have been doing while feeling out the tune.
My fuel milage was down 0.8 mpg this tank from stock, which probably has more to due with my right foot than the tune. Im sure when I start driving like a sane person again, it with go back to normal.
I will say, I was a little leary about tuning a car with 15,000 miles on it, but now I wish I would've done it 15,000 miles ago.
I hope this helps with your research.