Originally Posted by
windowontheAside
JFK to KEF is closer to six hours than four and it's overnight so comfort would be important to me and on that point I'd go WT+
That said, I've never transited at KEF, but I'd think it has to be a better experience than LHR so that could be a factor.
As others have said, I think I'd be tempted to spend some time in Reykjavik if the schedule permitted it.
KEF is a super simple transit point. Very clean and compact.
Couple years ago I did a stopover in Reykjavik on my way to AMS. Was interesting to see the geysers and waterfalls, soak in the blue lagoon.
Be prepared to suffer from sticker shock though. Iceland is EXPENSIVE.