I have flown long haul business class with KLM many times, probably more than 100 times.The cabin crew are amongst the best.
I always chose upper deck on the 747 but at the rear, maybe row 81.
Then you have a big wide windowcill locker to put all your bits and bobs in, briefcase etc..Nice seats, super service.
My regular routes were Hong Kong,Seoul,Kuala Lumpur, Singapore,Manilla,Tokyo,Jakarta, Sydney, Bangkok,Johannesburg.
Always the same standard of service.
I changed from BA for greater convenience so I could fly KLM all the way.
London Airways have lost the plot on this point.Besides, Schipol is much better than BA`s Fortress Heathrow.