I just did the same with about 6.ooo km, having heard a one hour dealers presentation by an renowned oil company about the different abilities of mineral, HTC synthesis and fully synthetic oil. They offer the whole range, but if you see the charts of the different qualities especially during the whole changing interval, the decision is clear.
Now I tried a fully synthetic Repsol oil (this was not the company with the presentation!) — the gearbox is so much smoother now!
I will stay with such an oil for our cars and my bikes.