I've had the Gear 300 in the transaxle for about 5 months now.
It is FINE, and it will protect the gears/bearings/etc. better than the DCT fluid will, especially in the heat of summer.
I am going to leave it in until it gets REALLY cold, just to see how much worse it makes shifting through the thicker fluid (vs. the DCT) in the winter.
IF that horrid, I will change it out for the Motul DCT I have in the basement already, or try some Ravenol, or Castrol Euro DCT or the like.