Thanks Pat! Long-time reader of STH, I really find your articles incredibly useful and informative!
I assume you meant to write "(so .48A on 120V)". 50W idle with 4 spinning drives, an M.2, and the redundant PSU really is really very impressive. As you say, keeping full load under 120 watts to be able to fit in a 1U/1amp colo gives an incredible value.
The hardware's not even that expensive! And for $50 - $60 / month in colo cost [1], the reliability of systems now with SSDs, and the amazing orchestration tools that are available, the likes of AWS, DigitalOcean, etc. start to look really expensive.