for your requirements a 29 is far superiour, I started out with a KH 24" for muni, it rules for really technical DH and north shore stuff. Then i got a cheapo nimbus 29 XC uni. It transformed much of my riding, which was slow and easy on the 24, in to much faster and more challenging. Other guys in my group believe that the 29 is also better for technical stuff, having rode the same sections several times on both unis. Certainly once a decent 29er tyre comes out I think 29 will be the size of choice for all muni.