Microwaving brown rice

A couple of years ago my father gave me a microwave rice cooker. It has worked like a charm for white rice, but I haven't gotten other rices down yet. I'm trying to fix that now.

I tried these directions from Steamy Kitchen. I had partial success. Previous attempts were undercooked, but this one seemed cooked enough to me. So I think I've got the times down: 10 minutes at 100%, then 20 minutes at 50% for 1 cup of rice. But they called for 3 cups of water and there was still water in the rice cooker when I was done. So I need to work on the ratios. I'll try 2.5 cups next time.