I used it back when BF was my LSP of choice for the S8. Nothing all that special IMO but an OK penultimate product for BF users and it might work OK under other sealants too.
FWIW, when I used BF it tended to *really* darken the paint, dunno how much this stuff contributed to that.
Oddly enough, what I use it for these days is prepping flat/matte/satin black finishes on undercarriages and in engine compartments- you know, the kind of parts that are often in pretty crappy condition with surface rust and so on. I clean the worse stuff off with solvents and then apply the BF GEP. It really does make such surfaces look a lot better, I was shocked. I'll apply BF or Collinite 845 over top and what-do-ya-know? the previously awful stuff actually looks sorta OK from a few feet back.
Sorry that the above isn't much of an answer...
