You will find that the top speed depends on how good your system is, especially the capabilities of your graphics card.
So before you start to write it off, perhaps the missing 10kts is a function of your system.
But what a fuss over an imaginary duck. Moaning because its top speed is a minute amount off on your system? Unbelievable! (Sorry, Victor Meldrew escaped and got to my keyboard).
It's a free gift. Say "thanks", not pick holes in it. Fancy getting wound up about a duck....