Both are pretty much similar.
TBH I've only ever applied them to my car - black diamond pearl. I found the FK1000P gave a kind of glassy look - a bit like the car was wrapped in clingfilm. The downside was that I felt it muted the flake. This wasn't much of a problem in dull overcast winter. The 476s was less shiny but allowed the flake to pop a bit better.
As always, follow the usual advice - apply thin layers and buff frequently, especially in this weather. In winter, I could do half the car and buff off. Leave it too long and both are a PITA to buff off.