In a completely unexpected turn, I just got my replacement 360 back today, a mere week and a half after sending the broken one in. The previous return took over four weeks to complete.
It’s another older refurb though (the serial numbers were so close I didn’t even realize it had changed on the support page), not a new one like I’d hoped, so I’m still wary. My last one was also a refurb with the new heatsink, and fat lot of good that did…