Sigma DP2 Performance Improvements

Shot to shot time in RAW is just under 3 seconds. Also, the LCD does not freeze, and it is possible to change settings during the period that one cannot yet shoot. Both are significant improvements from the DP1.

Source: DPReview forums

Regarding AF performance, Carl Rytterfalk had the following to say:

Also all above shots are taken using auto focus, I needed to see if I could trust it, and it seams to work very nice. And I must add that even if I feel that the DP2 is faster than the DP1 - it’s not a huge step forward. I would like it to be much faster still.

Source: Carl Rytterfalk Photography