Would be great to know the exact data set size (not size in the database). I can't get an order of magnitude sense of what I am looking at without that.

I know I can divine it from the parameters to stress, but I have no idea if the row keys generated by different clients overlap and I don't know the default number of columns nor their size.

I think it's also important in this kind of benchmark to describe the distribution of access especially for a read intensive benchmark. Without that you really don't know what your are looking at. I am a fan of scrambled Zipfian.