So far, like LSXPhotog, I just shot a session with both cameras and saw the difference when culling pictures. No side-by-side comparisons yet. But I'm going to do a few. The most important test for me is slightly underexposed pictures at very high ISOs. Lots of the test data you get in the databases online are shot at proper exposure, which doesn't separate out the cameras as well as forcing them to deal with underexposure. From the experience a couple evenings ago, I expect the R3 will come out noticeably ahead, but will be interesting to quantify.Did you do any side by side comparisons scaling up R3 images to R5 sizes to verify that the R5 has a significant advantage in this area? I (like everyone else) assume it probably does, but I haven't seen anyone put it to the test.