EQT Stage 1 here and the before and after of having the EQT DSG tune were impressive. I ran the car around for a week with ECU tune before receiving the DSG update file, it was manageable like that but felt like it was being held back at certain speeds and gears, shifts came at less smooth times.
Once the DSG tune was on the acceleration was much smoother in D, on ramps, highway passing etc became much smoother without having to manually kick down gears. Cut the lag/downshift time down noticeably and smoothened up the upshifts. Highly recommend it!