Yes, the ISO possibilities of the D5100 do seem attractive, I take most candid pictures at social gatherings without flash, and am happy to trade off a bit of grain against the intrusiveness of flashing in people's faces. Although the results might be a bit variable, it's sometimes possible to improve in post production if necessary. I am wondering if not so many people seem to recommend the D5100 simply because it is new and not many have had any experience of it, although the D90 does look very solid and more "serious". Thanks, Pavement Pilot!