With the CCX being 8 cores now instead of 4, I think the sweet spot will be the 8 core version. No need to worry about windows putting related threads on different CCX blocks..I guess with 10 core on the horizon, AMD has no choice but to whip out the big guns at launch, and not wait for a refresh to do 16 core. At least the 16-core 135w TDP does't look too crazy when you realize how many watts the 9900k draws.
Give me the 8-core version at slightly lower boost clocks, and you have a deal. The number of applications scaling efficiently beyond 16 threads is still pretty small, and will take some time to grow.
I'll take the best performance for my dollar TODAY please