The main difference between the ConneCTion and the ConneXion is that the first was made for the North American Market and the second was made for the European market (also sold in Oz/NZ).
So there are little differences tailored to the slight language differences in each culture - but no difference in the actual game of raising a Tama.
Version 2 is considered better because it has more features as tamagirl2458 has mentioned - the games are a little more complicated than the V1, but nothing that a 10year old couldn't master in an afternoon...!
Besides, in many markets I don't think you can buy a V1 anymore - unless you find a small shop that has stock that is about 12 months old!
Best, etc.
TamaMum