I'd say less important than a Masters 1000 tournament. A competition that has no history in tennis. A competition that was won by Nicolas Massu. It's always annoying to me when I see that somebody says, for example, "Rafa hasn't won WTF, but he won the Olympic gold medal. Federer and Djokovic won many WTFs, but they don't have the Olympic gold medal. It's true that Murray has won much less Grand Slams titles than the other 3 members of the Big 4, but he has the Olympic Gold medal" etc. For me, just above ATP 500.