KTF-Turbo posted many new image samples of the SOnnetar 25mm f/1.1 Micro Four Thirds lens: http://blogs.yahoo.co.jp/ktf_turbo/28265046.html. As you can see the image quality drmatically increases at f/1.4 aperture. F71.1 has a creamy effect and may be used for emrgency (or creative) reaosns only. I think it’s an impressive performance for such a tiny lens.
Reminder: The designer of the lens is designer Mr. Miyazaki. He is the creator of the well known Leica Triplet lenses (here on eBay) and already made a Sonnetar lens for Pentax Q mount which costs $650 on eBay (Click here)