Yeah, that Sony 50 is relatively large compared to that nice little 45. Granted, the 50 has OSS built in. I like Olympus' newer approach of thinning the lens barrel down a few millimeters past the mount. That looks nice.
Not really sure where a plus/minuses topic should go??
FWIW, here are some more good size comparisons from flickr user foxfoto_archives: LINK
I'm a little surprised that it looks like the Sigma DP1 Merrill isn't much smaller than the NEX-7 with essentially the same Sigma lens on it. That pic shows the kit zoom on the NEX-7, which is a solid 15-20mm longer than the Sigma 19.