The cyan corners are there, but they are not dramatic. They are more noticeable if you have lots of solid tones in your images, like white walls, blue sky etc. The nice thing is, and if you read Sean's review you might remember this, the 28mm ultron had the least amount of cyan drift of any of the 28mm lenses he tested. I mostly use the 35/1.4 ASPH and a lot of other of Leica's best optics, but the 28/1.9 holds its own. It is an excellent lens.
This is an example, but I think it is without the IR filter: