Went to Orlando via Detroit/Amsterdam/Norwich one year I really enjoyed it, the wife didn't, as they "lost" the bags on the return trip. They were actually on the next flight to Norwich and then they delivered them to our home address! Saved me lugging them to the car!
We arranged to meet a mate of mine who had been via Gatwick and we spent the same time travelling as we had a 20 min check-in at Norwich, and he had three hours plus the drive to Gatwick.
If the price was good I would really try to talk the wife round. The KLM flight to the states was fine, all the connections worked out well, in all "good".