Nice. It would have been interesting to dive into the exact differences in components. Are higher wattage PSUs in a series just using higher rated components or does the quality go up too?
Not really a fixed relationship between the two. Sometimes the entire blueprint of the PSU is from a different OEM. Corsair did this back in the day for a while where their HX750 PSUs were all made from a CWT design, and their 650/620W PSUs were a Seasonic design. I think this is less popular these days, but I think that's about as extreme as the difference gets.
At the component level, the focus is often on the sourcing and tolerances of the capacitors, which are used to clean up transients (very important) and power flow correction, among other things. I think the next most important components are the AC/DC conversion and the voltage transformers. Specifically for higher wattage PSUs vs lower wattage PSUs, the major difference is the amperage along the 12V rail.
At the component level, the focus is often on the sourcing and tolerances of the capacitors, which are used to clean up transients (very important) and power flow correction, among other things. I think the next most important components are the AC/DC conversion and the voltage transformers. Specifically for higher wattage PSUs vs lower wattage PSUs, the major difference is the amperage along the 12V rail.