Carbon fiber has much promise! However, since it is highly susceptible to impact damage. It simply should not be used for DH MTB racing at all. However, it's most probably the best road bike racing frame material, to date. Some XC MTB frames are made of CF. However, they have a ways to go before CF can be safely debuted into the DH racing bike circuit!

If you're not racing with CF, I can see no practical reason for using it while it's in its current technological state.

- Slim

PS.

Geez! Now that's it! I'm entirely too busy for anymore posts today!