Originally Posted by
RichardInSF
In fact, the re-arrangement of the Shinjuku south exit now makes it quite a hike to get from the Yamanote or Chuo line to the Narita Express. From the bridge, if you are going to the Narita express it is now much better not to enter through the South entrance but instead cross the street and go to the left for the New South (Shin Minami) entrance.
Bit off topic for this thread, but it's more the rearrangement last year of the N'Ex platform to Siberia (platforms 5-6) that is causing the problem. These platforms are fairly new, almost all the way to Yoyogi-eki, and not directly accessible from the South overpass -- instead you have to drop down to one of the Chuo line platforms (7-8), and then go under-over to get to the N'Ex platforms.
Best connection option is to use the East/West exists, which are connected to the Siberia platforms by just a long walk and then an escalator, or as you mention to use the New South/Southern Terrace bridge, which does serve all the platforms and is quite possibly the best JR-only connection option out there.