Well, actually, I would say it is pretty difficult to quantify! I have travelled a number of times in platinum to the USA and travel very regularly to London in business class (all with EL AL except for the occasional Virgin flight). I have only done it once in First (another one coming in 3 weeks). The difference is best described by how we felt after the flight. Apart from the very pleasant and relaxing flight and food, it was just as if we had not travelled at all. We arrived so refreshed that it was quite unbelievable.

Now, one thing I am pretty sure about with EL AL is that their upgrade policy is not just geared towards rewarding frequent flyers prepared to pay for a slightly more expensive ticket. It is also treated as a form of advertising. Once upgraded a few times, the likelihood that a passenger will pay for the more expensive cabin, either with money, or with points, is far, far, higher than it would have been before. I can tell you that from experience!