Originally posted by thibs numbers are just numbers. DA50-200 us a very fine lens. I can say so.
Their "peak score" is a strange beast, it's difficult to understand what it's really about, but it seems to put lightweight long zooms at a disadvantage. There are not many of those in the list, but strangely, a few more, e.g. Nikkor 55-200, show up when you use the compare function.
Here the DA50-200 is compared to the Nikon and Sony counterparts and on cameras with similar Sony sensors:
DxOMark - Compare lenses
The DA50-200's "lens metrics" look good compared to the other two, so how it ends up with a worse score I really don't know.