I hope you've resolved your dilemma, Dinosaurinmybelly.
I wanted to echo what Ferguson mentioned, which is that the choice is dependent on what kind of music the student enjoys more. You gotta love what you play. This is mainly from a motivational perspective (i.e. what the student will enjoy the most).
With regards to the suitability of a curriculum from a technical perspective (what you actually learn), most tend to be on an equal footing in my experience. Keep in mind that most styles of popular music, are derivative to a common root (Big Band), so learning the skill of playing in itself (e.g. coordination, technique, time) can be done through any curriculum. It's down to the teacher to make the material interesting, and well-rounded (by using extra material, etc).
Drummersmum and LooseAtTheSeams, I agree that the Rock School grades are great. The Trinity Guildhall curriculum is brilliant too. Ultimately, they're just paths that lead to the same outcome of playing drums, and developing musicianship.
I like to use either curriculum as well as just exploring the subject, and developing students, using a wide variety of material.
What's central to me, other than learning to play of course, is for the kids to learn to listen (to become good musicians), develop discipline (to maintain the skills they learn), and be good team players (to be able to work in an ensemble).
Apologies for the late comment, and likewise, the length of it!
Nick :)