My I-140 was submitted in June 2010 for EB1B. It was approved after one month in July. Then, my attorney submitted my I-485 in Sept 12, 2010. Dec 14, 2010, I rceived an RFE for my medical exam (original X-ray result) and Marriage Certificate problem. I mailed back RFEs on Jan 10, 2011; then my I-485 was approved two days later.
What I wanna tell is that RFE is not horrible at all. As long as you prepare the required documents, you will be approved finally.
Good luck to everybody here.