I've held the D60 and actually had the opposite response-the grip felt uncomfortable. Since I too got used to using cameras without any grip, using the left hand cradling the lens technique, what matters to me isn't the grip itself but whether it doesn't leave enough room between the lens and the grip for my fat fingers.
I have free use of a friend's Canon XSI. It's a little larger than the D60, but the shape of the grip is notably different, and for some reason the shutter release just feels oddly positioned to my hands.
The result is I still perfer using my little Kodak z712is. The Canon is a great camera, but I've gotten used to the Kodak and I just feel more comfortable taking pictures with it. No, the tiny sensor doesn't match the Canon output, especially with RAW. And of course there are other niggling things inherent in a sub $200 UltraZoom.
But I enjoy taking pictures with it an they seem to be decent ones:
(Had to throw my own cat shot in there ;-)
I have pretty big hands, and getting used to something as small as the z712is was a challenge (since my current film camera is a relatively "bulky" Minolta 430si). Now I haven't tried the feel of the E420 because I want a camera with IS. The E520 feels a tad small if I try to support it too much with the grip. But using the same type of hold I did with my various OMs, the camera feels nice. Yet, I may be an oddball, but I like that the new E-A1 is closer in size to the E3 than the E520.
People ask me why I want to stick with Olympus even after using the Canon. The answer is because of all the cameras I've used Nikon F2 and F3, FM and FG, Canon AE-1. A-1 F-1 and New F-1, Olympus OM-1, OM-2, OMPC and lately Minolta autofocus, The Olympus cameras have been the one that were most enjoyable to use.
The key is to go with the camera that will be just that: enjoyable to use. Honestly, in a given price range of dslrs, the pixel-peeping differences in IQ aren't going to matter that much in the bulk of most people's picture taking-and displaying-situations. Essentially, I make do with what best fits my hands-and my wallet-at the present time. As the saying goes "The best camera is the one you have with you..."