XD 40 Advice

I've had an XD 40 on layaway for about three weeks, black case, 2 12-round mags. When I put the gun on layaway, I looked at the date of the test fire on the envelope - August 9, 2004.
A good friend of mine works at the store and told me they just got a 15K order in which included the XD Gear-Up package (3 12-round mags, holster). He will change the layaway to the Gear-Up package for the same price-$430.
My question is, were there any significant changes between August 2004 and early February 2005 (the test fire month of the newer gun) that would be to my benefit to change the layaway to this newer gun (besides the obvious ones)? I thougt I had read here, or in a magazine, that there were some improvements on the XD in recent times (extractor or something). They may have been before the time frame I'm referring to, or not at all. The opinions of some of you Enthusiasts/Gunsperts would be greatly appreciated.

An addendum to the original post above:

The gun on layaway is the 4" service. I have the XD Gear-Up upgrade on the way from Springfield for my XD 9, so the tempermetnal holster and the extra mag are not the concern. As stated above, it was the real, or imagined refinements that have given me pause.

Again, your insights/advice/expertise are appreciated.