Processor Bus Speed vs. Memory Speed

Hello, I have searched for answers to this on several forums and have not found any concise answers.

Is it worth paying for a processor of bus speed 1066 MHz if the system memory to be used is only running at 800 MHz? In other words, will I be experiencing bottle necking/800MHz - level performance even with the 1066 MHz processing bus if the memory only runs at 800MHz?

I am trying to figure out if I might as well stick with a processor of bus 800 MHz instead of paying the extra $150 or so for a processor of a faster bus speed. Will I really feel the faster bus speed of the processor even when using DDR2 at 800 MHz instead of DDR3 at 1066MHz?

(The processor in question is an Intel Core 2 Duo T9550 (2.66GHz/1066Mhz FSB/6MB cache vs. Intel Core 2 Duo 2.60MHz/800Mhz FSB/6MB cache - using 4GB of DDR2 Dual Channel RAM at 800Mhz on a 64-bit Vista)

If there is any information I left out, let me know and I'll fill it in.

Thanks in advance for any helpful replies.