I'm now the proud owner of a Batis 25 (one of two people who own one in my country) >:-> and I've managed to do some tests. The lens is a beauty. The LED indicating focus distance and DOF is an eye-catcher, I think it's the first curious thing that people notice. The lens is fat but light. It's razor sharp from corner to corner -- at F2 -- based on preliminary tests I've done.
The 25 isn't coma free. It exhibits bat wing-like light aberrations especially when wide open, although they improve as you stop down starting at F2.8. The focus distance indicator is cool, although I hoped it was more precise -- the steps become bigger as the distance increases. An option for 0.1 unit increments across would have been nicer.
Here are some cropped photos to show the coma. I don't have star shots yet, but the city lights should give you an idea. The photos are uncorrected for distortion. Vignetting correction of 34% was applied in Lightroom. The full-size photos (42MP JPGs) are in this album.