It is interesting to see the little differences between these two models… The blue has the white horizontal lines under the logo on the left side. The gray has a ‘double slot system’ label on the right side that is missing in the blue. The blue has the little compartiment for batteries underneath and the gray doesn’t. also, I always thought the keyboards were exactly the same but you can see that the colors are different.
I always assumed the gray was the latest model of the two but comparing them side to side I think I was wrong. When I opened up both models the motherboard for the blue looked more recent (with fewer components). Functionality wise both are identical though. Hopefuly one day I will find the box for the blue model – I don’t think I’ve ever seen one of those for sale.