The new short northern runway at Frankfurt certainly seems to speed up european connections. I can't see any reason to visit Heathrow for connections instead. The same might be true for Amsterdam, if their satellite runway wasn't in Denmark.
I understand that Heathrow could squeeze out a bit more capacity by mixing takeoffs and landings simultaneously on north and south during times that are more heavily used by one than the other.
But what it does need is an extra runway, or two. An HS2-3-... train station inside wouldn't have been a bad idea either, slightly mitigating the sorry lack of a third runway. Amsterdam and Paris and Frankfurt and Zurich have all that sorted out already.