I own two GLOs, one from the first wave to reach Italy and the second bought after Mondadori sold them out and had to restock.
Here are some comparisons from the italian forum about Japan where I am mod (let me save some time by linking). Scroll down.
Yes, with the same firmware and the same slider setting, the older model has bluer lights which are also more powerful while the second one, apart from the mondadori personalization, have yellower lights which are also less powerful.