While the E-420 is a great camera, maybe you should wait with giving recommendations on how to buy the right camera until after you have yours and can really speak out of experience.
Why is there always one of you on every forum???......Well Mr. Prinz...to educate you....the E510/410 & E520/420 are virtually the same, the chief differences being image stabilization and a few "nice to have" operational features....the image components (i.e. sensor, microlenses, etc.) are the same...and in fact, if you turn off the IS on the 510/520 say like when its on a tripod....its the 410/420...simple isn't it .
So you see I do feel quite comfotable speaking to the IQ of the E420.....Thank you for yor concern as to my comfort though