Summary: Came in a suprisingly small box. The actual viewfinder is small - advantage is that it doesn't make the camera much bigger. Mine only had bright lines for the DP2's 45mm framing. It doesn't have 28mm brightlines and as such isn't suitable for the DP1M (which I have as well). The viewfinder is nice and clear with a reasonably sized view. It doesn't have any diopter adjustment so my view is slightly fuzzy - still very usable. It doesn't have any parallax correction at all.
Summary: Very clear viewfinder and works great. If you have both the DP-1 and DP-2 sigma cameras it would appear that this viewfinder will be suitable for both. Has screens for 28mm lens and DP-2 camera.