What are the key upgrades in the ASUS PN65 compared to the PN50?

The PN65 upgrades to HDMI 2.1 (up from 2.0) and 2.5GbE (up from Gigabit). HDMI 2.1 can drive a single 8K display or two 4K displays at 120 Hz each. The 2.5GbE port makes large file transfers go from “annoying” to “fine” for home server or NAS use.