I'm about to invest in the fully specced one because I currently have a small Dell Elite desktop running my Plex server on an older i5, which unnecessarily consumes a significant amount of power. I also appreciate the fact that the Pi 5 now features its own southbridge chip for IO (including cameras, displays, USB, Ethernet, UART, RTC, GPIO). This means that the Pi Foundation can now update the CPU and IO independently. Consequently, there's a possibility of a 'Pi 5+' in the future (around 2025-2026), with either updated IO or an updated CPU.
What a time to be alive
Additional sources: https://techcrunch.com/2023/09/27/raspberry-pi-5/