It seems that with Intel's Lynnfield hitting the shelves now, AMD is trying to get as many CPU's as they can out to compete.
While it's a good effort by AMD to keep the line up and running, it really seems that the days of K10 are numbered in terms of performance crowns. AMD needs to really make things up in volume and keep prices as low as possible to make their CPU's more attractive.
AMD's Athlon II is no technological marvel - it doesn't support any new features that the Phenom II already has, in fact it's been stripped of its L3 cache, so any thoughts of this CPU being the savior are gone. This is purely a mainstream product designed to keep AMD in the game.
The one thing that the Athlon II has in abundance is overclocking headroom. Our stock sample 2.6 GHz part was able to hit 3.9 GHz on air. And maybe with better cooling, more time and some fine tuning, overclocking to 4 GHz and beyond might be obtainable.
To us it seems that the L3 cache on Phenom II processors hampers the clock speeds quite a bit. We used the same motherboard that we overclocked the Phenom II with; it only managed a few megahertz extra FSB to increase in speed. But with the Athlon II, we managed to clock things right to the max, as we had to rely on FSB as the multipliers were locked.
AMD Athlon II is a cheap overclocking CPU that really isn't worth it at stock, the real gem of this CPU is the ability to overclock. If you're going to stick only to stock clock speeds go with the Phenom II, but for overclocking take the Athlon II and clock it through the roof.