I never ate a horse, but my cousin was forced to either eat horse or starve years ago when he was in some remote 3rd world place in the military. He said that it is very poor quality meat and tastes bad. He said that it was similar to moose meat, which I hate. (I don't hate all wild game, but moose doesn't agree with my palate.)
Celeste a lot of the meat's flavor depends on what and how often an animal is fed. Good example for me are deer. The deer we harvest have a good flavor, but they regularly feed on corn and soybeans. Go farther west and they get into sage and their meat tends to have a sage flavor to it that I cannot stand.