E-5 and E-510

I am thinking of upgrading from an E-510 which I have had for 5 years to an E-5. Before I make that move I would like to hear from some of you who have had the E-510 and now have the E-5. What are some of the main improvements that you have noticed regarding image quality, ease of use, and other factors. This camera body is expensive and I want to know what to expect. I have 5 lenses. My favorites are the 70-300 mm and the 12-60 mm. Thanks.