This morning, took my son out to Heritage Park, a local park that's a little more than just a sandbox and swings. I felt a little rusty framing and composing for the 28mm, but still came away with a few keepers.
To be honest, I can't really say that the 28mm Summicron is that much different from the 28mm Elmarit-M ASPH. I do feel the color and contrast is a bit more punchy and crisper, and the extra stop will come in handy indoor and dimmer scenes. Size-wise, the 28mm Elmarit-M ASPH is much smaller because of the oversized hood of the 28mm Summicron, but I've read that others have simply used a smaller 46mm screw-on hood instead. It'll be a hard choice to make, but I don't have to make it today ;-)