A useful feature of GSPro that HTH lacks is for fairway conditions. Since fairways can change considerably throughout the year, this feature on GSPro is very useful for making the simulator more lifelike.
Setting range from...
Soft, which is very useful when practicing for play after a rainy day,
to
Links, which is great for simulating hard fairways that roll out a long ways.
There are several speeds in between which are good for varying conditions. Since one of the main things I use the launch monitor for is practicing for upcoming rounds, the fairway speed is quite important.