I'm posting this question to both the American and Delta forums. It looks like this year I'll wind up at both Executive Platinum on American, and Platinum Medallion on Delta. I hope to not fly quite so much next year... Which airline should I do most of my flying on?

I fly out of JFK and LGA. A frequent run is JFK-SFO, but I also go a bit to Europe (where Delta has much better JFK schedules) and Asia and Australia (where American wins). I like the free wine in Delta Crown Room Clubs, and the fact that they are free (this year) and cheaper (next year) compared to the Admiral's Club. For JFK-SFO, I've very often been bumped up on Delta while finding it harder to get on the list to use upgrade points as a plain Platinum on American. I'm more confident I will fly at least 75K miles next year to remain Platinum on Delta, and less confident that I could hit the 100K mark on American. American seems to be on more stable financial footing than Delta. I've received a fair number of free upgrades on JFK-Europe flights on Delta, but then again I think it's easier to do a modest miles/$ upgrade on American (I just spent 25K miles/$250 for business class JFK-NRT). I found it easier to get 25K award tickets on American than Delta in recent attempts.

Suggestions?