New Zealand has been waiting a while for 3rd Gen, which was released quite some time ago overseas.
Essentially, the ‘upgrade’ from a 2nd Generation Hue bulb is that you gain a proper Green and Blue. The latter shade isn't particularly bright, but at least unlike the previous Gen, it does look blue. 3rd Gen bulbs also dim to a lower level than 2nd Gen.
I don't particularly notice that any of the other shades are that much ‘richer’, but while you gain green and blue, you do lose any shade of purple in the process. While that shade wasn't particularly rich in 2nd Gen, it was there, but 3rd Gen Hue seems to go straight from the blues into pinks. Just something to consider if you're a fan of purple, which the Hue Go lights also don't do particularly well.
Otherwise a worthy upgrade, in particular if you're after some greens and blues.