Well out of all these benchmarks on both pages the 810 only beats the 720 in 2 running stock. The 720 wins 11 benchmarks.
http://ixbtlabs.com/articles3/cpu/amd-phenom-2-720-810-920-p2.html
For example, the 810 processor looks much better than the Q8200 and the Q6600, which has a much larger cache. Phenom II X3 has a significant advantage -- the third core. So it's a more promising product, demonstrating no worse, or even better performance in most tests. In fact, this processor makes dual-core CPUs justified only in the budget category, which lacks triple-core models, or in case of some specific tasks.