I'd say the F30/F31 is fantastic up to ISO 400, good at ISO 800, and barely usable at ISO 1600 (unless taking photos in broad daylight where the noise isn't as evident). In comparison, other compact p&s cameras are unusable at ISO 800 and beyond. I'll hold onto my Fuji for as long as I can.
I have the F31fd, and would definitely go for the Sigma DP1 if it was financially possible. It may handle slowly when compared to a DSLR or some other compacts, but "slow" is relative. There are normal p&s cameras that are just as slow. My Fuji isn't particularly fast, and its menu system is unintuitive and rubbish.
My friend's Panasonic is dog slow. I'd accept a slightly slower camera if it was capable of good image quality and dynamic range. The DP1 delivers, particularly in terms of highlight DR. The images are sharp sharp sharp! Just look at THESE images. The result is far beyond what most cameras are capable of. Overall, when compared to other "quirky" cameras (translation: p&s that tries to be more), the DP1 seems to be wonderful. It would probably be fantastic for landscapes, producing wonderful blue skies with its high DR.
The noise issue in the DPReview review was a bit blown out of proportion, IMO. In fact, I think the reviewer was a being a bit daft in some of the conclusions he drew. People who don't know enough about photography seem to state the DPR reviewer's comments as "fact". Draw your own conclusions. If you ignore the text and strictly look at the images produced by the DP1 compared to the competitors, the image quality is obviously excellent in every comparison. The exception is when the reviewer tried to upscale his 4.7 MP image to a whopping 13.9 MP......as if that's a realistic size to upscale to. (What if I want to upscale to 8, 9, or 10 MP, which is perfect for most applications?) The noise doesn't hurt the image quality because the noise doesn't look particularly bad. If you're particularly anal about noise, then go nuts on the noise reduction (particularly on the chroma noise). The photos are sharp enough to allow for a bit of the blur associated with NR.
