Every truck built is a little different, as are the conditions we drive them in; not surprising one tuner works better than others in a given situation.
I like that the SC has a dedicated towing tune. HF says their 89 tune is fine for towing, but that's not the same as a dedicated tune with presumably higher knock watch etc.
I'm close to enough to end of warranty that if/when I find $1000 I'm ready for a DS w/custom.