Which one is better in performance
Intel Core 2 Duo E6400 2.13GHz with 2MB L2 Cache
Intel Pentium D 945 3.4GHz with 4MB (2x2MB) L2 Cache
The E6400 is also $200 at most retailers. The E6750 will out perform it for $180. The 6550 is just $175.
Anything is going to be better than Netburst though.