I've used FK 1000p on and off for a few years now. Very good stuff, but I agree it is a bit hard to work with.
It is excellent at repelling/releasing dirt and grime. It looks best on lighter colors.
I had previously tried 845 on my yellow SS paint and for some reason I had a lot of difficulty in application/removal.
I just tried it again yesterday on my wife's silver car, and I have to say that I was very pleased with the results. It applied easily and removed even easier, and the initial appearance was *very* good on the silver. Nice and bright, reflective and wet. I'm used to sealants where the appearance doesn't really show itself until the next day, but 845 looked great immediately.
Looked at my wife's car today, and it looks clean, no dust to speak of, so it doesn't look to be a dust magnet either.
Obviously I can't comment on it's ability to repel dirt/grime or it's longevity, but based on *numerous* reviews/posts about this product over many years, I really don't think you can go wrong with 845, and you can't go wrong with the 1000p either.