The X6800 would be the better chip in theory, since it is
- higher clockspeed, thus bad smp scaling apps such as game are better
- unlocked multi (QX6700 has it too)
- less heat, thus should overclock better
In practice, however:
- Pricing the X6800 as it is is a total joke. Only insane people would buy it.
- The unlocked multiplier and the less heat don't buy you anything since recently delivered dual-cores don't overclock much if any.
- It is only 2.93 GHz, when e.g. Woodcrests are available with 3.0 GHz. Joke.