I plan to try the "baking test" on the failed capacitor, not done yet.
I also have not gone back to the roof to see how the new one is labeled. The BOX says "IEC 252 Class B Reliability" and "Assm in Mexico."
Can't find the IEC-252 spec on gOOgle, but it seems the premium spec is EIA-456-A with 60,000 hour reliability.
The one I installed, ordered on Amazon is a Proline Brand, and IEC-252 as noted. I plan to get another capacitor to carry as spare. So far I've found Genteq, formerly GE, that's IEC-456-A. If it's actually a higher spec, I'll install he Genteq and drop the Proline back to onboard spare status.
I'd love to hear from anybody with details on these specs. I do know that I had a couple home HVAC capacitor failures and took a failed one to a different parts house. Countergirl said the one that failed had a much lower hours rating than the line they carried. And their price was LESS!