The Sigma DP1 delivers on its promise of excellent image quality, but this is overshadowed by disappointing handling. The autofocus is simply too slow for a camera at this price, and it is made worse by the fact that the preview image freezes while focus is acquired. These problems combine to make it very difficult to focus and frame the image properly in dynamic situations.
Other issues are the rather slow write speed for RAW files...3 seconds, even with a SanDisk Extreme III card and the fact that it takes too many button presses to change the ISO.
If we can have dramatically better handling in compact SLRs at the same price-point, why can't the DP1 match that? (I know SLR's use a completely different focusing mechanism, so it may be hard for a compact to completely match their focus speed). But at a minimum, the DP1 should be at the top of the performance charts in every category when compared to other compacts. The fact that it's only average is disappointing.
I wanted to love the DP1, but I've returned mine. I think the real problem is Sigma's lack of experience with compacts. Please, Canon, Nikon, someone...take the sensor and image processing pipeline from one of your 1.5x crop compact SLR's and build us the DP1 we really want!