I would say 3M color stable over Sungard products. I'm not even sure what Sungard makes for auto film today. They were acquired by Madico about 2 years ago. On the Sungard website they no longer identify their specific automotive tint products.
http://www.sun-gard.com/automotive-window-film
My guess is that Sungard product today is rebranded Madico.
http://www.madico.com/window-film/automotive/
I think Wincos is the only Madico product competitive with 3M color stable or crystalline. And in my experience Wincos has a blue hue to it that may not be pleasing to your eye (when looking outside). Their other films are either dyed or metal.
BTW, you live in Canada. You likely don't need 20% VLT film unless you really want privacy. I'd stick with 35% VLT or greater in Canada.