So a month later, my computer is still just peachy. I even took it on a seven hour road trip (one way, so really 14hrs) in its original box when I went to my parents' house for a week and it was fine there. Yesterday it was pushed pretty hard as I was exporting and converting videos.
The only problem I discovered after the PSU swap is that somehow my boys did not get the microphone back where it was supposed to be, and it no longer works. But I bought a $14 USB one to fix that problem. My class materials were all uploaded last night to the vendor, so now I can wait out the actual 27" replacement. 🙂