I had my top holes up to 1/2" and the bottom ones to 9/16" and finally had to give up the top ones because my lobes are just too small to handle that much pressure. The skin between the two started to split and if I tried using soft plugs then they would just get squished by the pressure.
So I gave up the top holes and continued stretching the bottom. In about 6 months I went from the 9/16" all the way up to the 1 1/4" I've got now and the 1/2" top holes have shrunken down to 0g but don't seem to have gotten any smaller over the last 6 months.