I use the Idemitsu Subaru 0w20 and am going to change to the Mazda with moly in it when I hit around 10k as well. I work for Idemitsu and both oils are very good oils. I don't think one is better than the other except that the moly is a bit better for things like the cams and followers. It's also nice that I get free oil as well.
I usually like to change the oil every 3k miles since we don't drive very much. I have about 3700 miles on it now. We bought it in May of this year.