The real star of the game is (of course) the racing. You can choose your tactics, skip past the announcer's blah blah blah and see how your horse does. My only problem is that the course preview doesn't show the curves of the track like Grand Prix Story. The mechanics of training for a race are simple- your horses use your training facilities and you can use special training at the cost of money/medals(the 'research points' for this game) and fatigue. You can also research, equip and upgrade abilities such as 'speed'.
The base horses you can buy are pretty dire, but luckily, due to the breeding mechanic, you can create much better horses. This mechanic really shines as it lets the player tinker around. I noted that Pyraplex was disappointing before, and the reason was that you could get everything on the first playthrough. Pocket Stables much improves on this. I have not won a triple crown yet, but I'm still working on it. I also enjoy the attention to detail- the backwards walking sprites on the observation deck, the odd little indicators of the horse breed(a fro for bouffant, a little top hat for noblesse), and the strange breaks from reality such as the fact that people apparently pay over $10 to take cell phone pictures of your ranch.
Yes, Kairosoft has a formula, and if you like the formula, you'll like most of the games. I enjoy these lo fi sims which allow you to play either for a few minutes or a few hours. I find their games soothing- usually I mute the music on Kairosoft games but for Pocket Stables I like to listen to the soothing music as the visitors, horses and jockeys go about their tiny business.
I find as I get older the games I want to play are more retro in style. Smaller, cheaper, less stimulation. Pocket Stables keeps the faith.