I have used this lens for serval months. I think it is very sharp and has a very high quality. But the most important is that it is very cheap and very light. I use this lens on 30D and 30V. When I use it on the 30V I must use a conversion ring which enable me use the CY lens on the EOS body. When I use it on the 30D, it become 45mm which makes me can use it to photo landscaple and architecture very convenient.
But the reason I use it is the high quality of this lens. The resolving power of it is on a high level. The color of it is very pure. This lens is also very sharp. But its color is not so vivid as the D25's. But I still very like this lens.
I want to take more photos by this lens. And find more characteristics of it.