If it may be under warranty still, which means oem product put in, and not necessarily better either. But in the case of warranty it is.
And by what caveman said being a first time, this is really where you drive more 'aggressively' and I know for a fact that you can't for the life of anything get that shifter into 3rd or 4th at high rpm's in EASY with stock trans fluid. It's different from driving on the highway, you step on it, and go into next gear, but not as 'forgiving' with it, especially when rpm's are just under 5k.
Plus, there is a lot of contributing factors, as is maintenence, and heat and driving style, parts, etc.