I agree. I saw a pretty big increase by moving to quad core from dual core. I was always like: "meh...apps aren't optimized for 4 cores yet" before I actually got one and saw the boost in performance. But seriously the Q6600 would be a better investment.
As far as the i7 goes....wait. They will be releasing 8 cores soon and the prices are way too outrageous right now. An X58 mobo is still over $300 and triple channel DDR3 is $300 as well (6gb kits). I also read that the new Intel SSD's are as much of an improvement or more than the i7's in new PC's. Considering they are $600 that is also a rediculous price to pay to have the newest, but not necessarily the best.
As far as the i7 goes....wait. They will be releasing 8 cores soon and the prices are way too outrageous right now. An X58 mobo is still over $300 and triple channel DDR3 is $300 as well (6gb kits). I also read that the new Intel SSD's are as much of an improvement or more than the i7's in new PC's. Considering they are $600 that is also a rediculous price to pay to have the newest, but not necessarily the best.