You have a lot more space for scaping and corals. More water volume means easier stability and problems will take longer to be established. You will many more options for fish.
The only Cons are it will cost more to run. More electricity and salt as well as additives. More glass to clean and more sand to vacuum.
IMHO a 150 - 180 is the perfect tank size if you have the room. The equipment doesn't get overly expensive and is readily available.