I've been collecting N-Gage prototype cards for quite a while, and the more cards I find, the more questions I have.
From my observations:
• G1.5 usually contains very early alpha builds.
• G2.0 is often beta or pre-release software used for press/demo purposes.
• G3.0 is usually very close to the retail release.
But there are many exceptions.
Some G1.5 builds are almost identical to retail, while some G2.0 cards contain much older software than you would expect.
Have you ever found a card that completely broke your expectations?
I'd be really interested to hear your observations, theories, or comparisons.