Both definately have their perks, but I have to go with flying because on the physics of Portal by Valve they have not indicated teleporting has any affect on momentum/inertia of the object. I see teleporting as basically able to open both a orange and blue portal at the same time anywhere you want. As for the momentum problem, if you are in a car doing 60 Mph and you go over a cliff, if you teleport out of the car and onto the cliff you would still have the momentum of the 60 mph and youd get messed up hitting the ground and rolling on that speed possibly going over the cliff again depending where you teleported to.
But since this all conjecture on a hypothetical ability, I can freely admit to having no shame basing my opinion mainly on just a video game
But since this all conjecture on a hypothetical ability, I can freely admit to having no shame basing my opinion mainly on just a video game