There's a lot of talk on different forums on the web that the Olympus mZD 75-300 is not sharp and the Panasonic 100-300 beats it hands down. I personally can't agree with this and as you can see, this image is quite sharp (even though it is quite small). I have found the images from both lenses to be very good.
BTW, this image was shot on an E-P2 handheld. The mood was particularly clear on this evening. I just couldn't help myself. Just like when some clouds come over. I have to get my camera out and capture them for eternity.