For me it was the best deal at the time and it felt good in my hand. Arround Jan 08 the E510 easily had the best features for the price. I wrote all about it
here on my blog if you want the whole details behind my choice.
I still love the camera but don't think the new E520 represnets the same value. Canon and Nikon have added all of the features to their new models the made the E510 stand out and when you couple this with the extra lenses available at cheaper prices the olympus no longer stands out. When you then consider the better low ISO performace of the Canikons it does not seem the best option to go Olympus. The only thing it really has going is the quality of the kit lens. Plus I really hate the 4/3rd aspect ratio and end up cropping all my shots to 3:2.