I hate to be the bearer of bad new Nigel, but I am not certain that one single manufacturer has ever been realistic in their published numbers.
Its all smoke and mirrors for the real world performance.
You can't just whip out a calculator and do some basic math and say, yup, i'm gonna lift that.
Theres alot more to consider. And in most cases it falls short on expectations.
I'm still not sure why you're so pumped for it. are you looking at production longlinging at some point? or just lifting some camping gear once in a blue moon across a river?
Its like a guy buying a ferrari and excited to put a tow bar on it so he can pull a utility trailer to the cottage.