You should not really appreciate it, since it is total nonsense, as the experience of thousands of user who overclock N900 (and many more who overclock similar devices with the same CPU shows).
Still, not even one device damaged by overclocking is known.

On the other hand, you should be very wary of USB host mode. The USB connector is known to be very problematic, so the extra connections and disconnections are sure to reduce you device's useful life span. And when you go to Nokia service with the broken USB connection, they will fix it (or not, as they please).