I can't recall where, but I do remember that some new tech is derived from archaeological finds...
I think the Astral Rifts or Gateways should be considered easier, as they rarely take a physical form to the Astral, only the astral form. Point-to-point portal magic is more complicated, as it must guarantee travel through at least the astral. I'm imagining it going through much worse places (Event Horizon and Doom3 both cover this possibility...).
From a purely game-play perspective, teleportals open a severely dangerous precedent. Insertion into locations would become, at best, much harder, and T-bird jammers would be out of a job. I imagine the only mitigating factor would be expense and availability of tech. Even then, the only two HUGE rules for magic in SR is that it cannot bend/break the space/time continuum, and that it cannot bring the dead back to life (just two more of the mistakes the poorly-linked 360 game made..). I know the 4th Age had resurrection magic, but only at the very HEIGHT of their mana cycle, which is a good 2000 years away, and it was almost impossible even THEN. And by that time, the magic was so rich there were much, MUCH scarier things taking place. I think portal tech would be about the same. If we DO see portals, they'll be more technological than magical, by my guess.