I dunno about performance. But I sure like the smell of the orange stuff. Simple green in close quarters makes me have breathing difficulties, all wheezy like.
I have in the past degreased cars from stem to stern immaculately, like a virgin, with Simple Green. I mean oily, greasy, beaters looked like new when I was done. The Simple Green smell hangs on for a few days, though. And I would get plenty of fresh air.
The Orange stuff I have simply not used it on an entire car. I few spots and it seemed to work OK, nothing miraculous - maybe equal to Simple Green.
One thing for sure, both are better than the nasty old "Gunk" spray foamy or not....To think 20 - 30 years ago I used to use that solvent stuff. Smelled for a week or three.