That's debatable.
No it is not debatable
Please check the reviews, Q6600 is clearly better than 9900 on average
AnandTech: AMD's Phenom Unveiled: A Somber Farewell to K8
the 9700 is only slightly behind the Q6600.
For me it doesn't seem slightly behind. It is about %10-15 behind, thats just like the difference between E6750 and E6550 (or 6000+)