Looking to Upgrade my E-510

I can only speak up for an E-30 upgrade. I switched from the E-520 and I saw a significant change of lens speed when using it with the lenses: 50mm f2, 70300mm ED. I had it for almost 4 years and I can tell you that was my best purchase as far as camera gear. Pair it with the Oly grip and you'll get a more stabilized body cam for landscaping and portraits.

Forgot to add, I also found that the E-30 handles higher ISO captures way better than the E-520.