The oil paints work extremely well to paint horses. The colors and subtle and smooth transitions look great to me. I recall painting some horses for a medieval caravan several years back and recall being fairly unsatisfied with the flat results and lack of realism.
While slapping a base coat on followed by some sort of brown wash gets models on the table for games, enjoying the process was always lacking for me - until now. I am really looking forward to painting the horses for the Zombicide: Undead or Alive game!