This lens is available in at least two different versions. Pictured left is the newer version, and the optical formula has changed compared to the older version. Paulien shows on her MSX/DSX website two versions of the old lens design (only cosmetical differences).
I haven´t had a chance to test this lens yet, but I would assume that the newer version has improved its optical quality compared to the previous version.
The lens data of the old version is listed further down below.