Harlock I must say the 3 Specialisations in Stay on Target are wonderful Edge Specs; Hotshot is an amazing Corellian, Rigger is fantastic for Bounty Hunters who love their ship, and Beast Rider fits everywhere. The ships are great, the gear is great, the Beast Riding is great. The only thing you miss out on is themed text filled with fluff about living on the edge of society and more Obligation options.
Just because it's in an AoR book doesn't mean you can't use a huge amount of the material, of all the AoR books I would absolutely recommend your group add it to the library, especially if being a beast rider is important to someone. Just build the character using EotE creation rules, but stick to the skill limits of the career, or pick the Spec up as a second spec to add to an existing character.
For a simple run down on riding it's basically Piloting using the Survival skill. Beasts get a speed and handling based on their characteristics, and must be Silhouette 2 or more. There is training rules too to tame a mount to be easier to handle. There are a ton of the classic Star Wars riding beasts in there too.