I've handled both versions of the weapon, on a SUE in 2001 where I spent several days on the range with it, and again in Bosnia earlier this year. Most of the modifications I noted were cosmetic or insignificant. You still destroy the weapon if you put a pin in the wrong position, although I didn't gash my hand up nearly as badly on the ejection port cover this time, partly because I remembered (mostly) to do the drills with my left hand, and partly because they took off some of the razor edges on the cover.
I will say, that as a medic climbing in and out of the vehicles, the shortness of the bullpup was appreciated, and, while I never had any problems with performance once I could get a good fire position, Hythe Ranges were hardly a realisitic field test.
The Grenadiers I spoke to were still none too impressed with it, and envied us our C7 and -8's.
DF