I know that this has likely been beat to death but I can't seem find what will be the precise differences between Elite 35k and 50k for 2013. I'm at 45k presently so for me it's whether or not it's worth taking a trip for a few days to earn 5k. Does someone have all of this info listed? Apparently one will still be able to get full lounge access with 35k. What about upgrades? Your help would be appreciated.