I run a I7 920 oc'd to 4ghz. I can hit 4.2, but I sometimes lose stability. at 4ghz I run Cubase 5.1 (im VERY anxious to see how the new 5.5 cubase update will help my performance, they claim better multicore support)
6gz's of top quality ram.
depending on what plugins are running, I can run at 64 samples ~2-3ms latency using Centrance tester without any issues.
In fact, I can load up a TON of instances of SSL channel strip and my guitar sims and be laughing!
However, toss in a plugin that doesnt like low latency, and you will get pops and clicks.
When I do a check as to how much CPU is being utilised, it seems like even with a full load and a lot being done, my I7 is hardly breaking a sweat.
Joey, if I were you id overclock an I7, and down the road, you can simply do the upgrades on Mobo/CPU/Ram. I cant see the 6 core making an epic difference considering that even a decent workload in Cubase on an I7 barely makes it sweat!
It's too bad that the Ultra high end is so much more, and the price DOESNT reflect the speed increase!
Save your beans, I bet in a years time the 6 core will be half the price, and I cant see you fully using its potential.
However, your work needs are a lot different then mine as a hobbyist, but thats just my input