I know this is splitting hairs, but I'm using the
AI Nikkor 50mm f/1.8S, the Japanese domestic market (JDM) version that focuses down to 0.45m. The Series E 50mm f/1.8 is its predecessor, sister lens that was "designed with the same basic optics, but different outward appearance and coatings." There's a
thread here on the forum about the JDM version. Apart from it being multi-coated compared to the single-coated Series E lens, the only other practical difference IMHO is closer minimum focus. At the end of the day, I doubt I could tell the difference in photos.