The reason why Oblivion's system sucked was because enemies not only got stronger when they leveled, they also gained better equipment. The HP gain for enemy leveling was also insane, making higher level fights drag on forever.
Dragon Age doesn't seem to have these problem. Enemies don't get stronger equipment as they level up and it takes about the same amount of time for a level 20 Inquisitor to kill a level 20 red templar as it does for a level 10 Inquisitor to kill a level 10 red templar. Even less depending on how you make your build. That's what makes the game a great candidate for level scaling.
There's certainly room for a Hardcore mode featuring non stop enemy level scaling for those who prefer that. A gradual increase of enemy AI as you progress and level up might work better. So you would not only fight enemies with higher damage output and threshold, but these same enemies would also fight smarter. Higher leveled enemies using teamwork tactics like flanking, laying down runes, and playing off of each other's strengths.
For instance if you fight a mob of mages and warriors at level 10, this same mob at level 20 would be using more intricate tactics. Like one enemy mage using a barrier, spamming 'weakness to ice' spells at your party, while buff enchanting nearby enemy warrior companions who flank your party instead of charging you head on.
Another enemy mage runs around laying down frost runes and uses dispel to counter any barriers you have, as another enemy warrior tries to force your party members into the frost runes. So even though you will have better stats at you level up, you would now have to fight smarter instead of spamming your favorite moves over and over.