For me, I still see better DR from the APS sensors like the Pentax K5 than the smaller mu43 sensors. I'm basing this on what I see posted in this forum and the mu43 forum vs. the K5 shots I see on the Pentax mailing list. The latter still seem to my eye to have a more subtle range of gradations whereas mu43 sometimes looks a bit "clipped", especially the highlights. Mind you, I use almost exclusively mu43 and smaller sensor cameras like the X10, so I'm happy with these results. I just can't help but notice the differences. I suspect that as sensor technology improves further, however, these differences in DR will become increasingly moot in most situations.