I'm upgrading from an old 2.4Ghz P4 478 chip, so I guessing even the 4400 will be a big leap for me?
I went from a P4@2.4ghz on a socket 478 dell (which my parents use now) to my C2duo E6400. I LOVE THIS CHIP!
Either way, (even the E4400) a core 2 duo chip will outperform that P4 by at least double....(or so I think).
You won't be disappointed by the c2duo..