iXBT Labs published a review on the AMD Phenom II X3 720 / X4 810 / X4 920 processors

We can conclude that Phenom II processors demonstrate more attractive performance than their direct competitors from the Core 2 series. For example, the 810 processor looks much better than Q8200 and Q6600 that has a much larger cache.

AMD Phenom II X3 720 / X4 810 / X4 920 Review