Hi Del,
I don't think either one is "better". They are just two detectors that offer roughly equivalent performance but with slightly different feature sets. I think I can find gold about as well with either of them. It is the features they each offer that are intended for coin or relic hunting that most differentiates them.
For instance, the F19 offers mono or dual tone modes. The Racer has mono, dual, and three tone modes. The three tone mode might appeal to somebody.
Or in the case of the Racer, the "break point" between the tones (low tone ferrous, high tone non-ferrous) in dual tone mode is preset. On the F19 the break point can be shifted up and down. So low tone could be set to be all items reading below a nickel, and high tone everything from nickel on up. That feature might appeal to somebody.
So my advice is not to buy one or the other because it is better at finding gold. They are very, very close in that department and if either has an edge it will be site specific. Instead look hard at all the other features they have and see if anything on either unit really tickles your fancy.