Note: I don't own an OM-D. But I do own a 25mm Summilux 1.4 and I love it.
If you are shooting micro four thirds, and you have a preference for "normal" focal lengths you'll find this lens to be an absolute treasure. After I shot with this lens I gleefully sold my Panasonic 20mm 1.7 to a friend and haven't had even a glimmer of remorse. The images below
are from a casual afternoon out and around with the 25mm Panasonic/Leica 1.4 Summilux attached to the front of a Panasonic G3. Set (as the Photo Gods intended) to shoot in a square format.... I think the images are also a testament to the G3. Which is adorable.