Nokia 7500 vs 7900

As you all probably know Nokia announced the 7500 and 7900 for the world. They are both part of the new Prism series which consists of a design based on triangles. the 7500 was released earlier in China. Both phones are very similar in design but I think the 7900 looks sleeker. The 7900 has smaller keys...wonder if it makes them harder to use. The 7900 is smaller and thinner than the 7500, loses