I don't think the Q6600 is actually all that much better than a your i3. The i3 is 3 years newer, much smaller lithography (32nm vs 65nm) with substantially better IPC and although it doesn't have 4 cores, it does have hyperthreading (handling 4 threads) which helps bridge the gap between dual and quad cores in both productivity and gaming (that's why modern dual core i3s can still hold their own in games where the Pentiums really struggle)
Anandtech Bench doesn't have your exact CPU, but it does have the i3 530 which is the same architecture, just clocked a bit higher. You can see the comparison between the i3 530 and the q6600 here:
http://www.anandtech.com/bench/product/118?vs=53
You can see in the benchmarks that in both...