Almost forgot to reply to this, hope I'm not too late.. Jolly has always been far better on Garchomp because 102 Speed is just enough to beat a lot of important things like Salamence, Jirachi, Lucario, Roserade, and Gliscor. This generation it's even more important because Sazandora, Landlos, Ulgamoth, and Adamant Kojondo are around, along with Ninetales being more common.