agreed, you will not notice a difference between the two processors. depending on the stepping of yours, they probably both have the same architecture and cache sizes, with the only difference being clock speed. You could probably overclock your current cpu to almost the same speed as the 5600+.
your cpu is 2200Mhz,
the X5600 is 2800Mhz.
that might seem like a big difference, but with the old architecture it hardly makes a difference.