The upgrade offer from J to F for one of my flights changed now to $600 (it was $1200 until now). It is from JFK on a 14-hour flight on 77W. I have heard some people here and elsewhere say there is better privacy in J than in F. So, though the offer is very attractive, I am wondering if anyone has any suggestions or reasons why I should stick to J. My primary considerations are privacy and quiet. I am currently in the mini J section. I also value service, but that is so very crew-dependent on US carriers, so I will not upgrade for that.