latest postfix vs. postfix 2.3 package?

[Dave]

Hello,
        I'm running postfix 2.3 via rpm package. This is on a centos box. I
know that there are later versions out, and am wondering if there's a
feature add-ons page, not just a changelog, something very detailed version
to version,  that goes in to detail? I'm trying to decide if i should do an
upgrade.
        Thanks.
        Dave.