And here is initial stage of HD6950 ffa_block=ffa_block_fetch parameters curve. Again, it's clear that minimal default params not good for this GPU, more domain size for FFA kernels required. Red vertical line marks point where each CU will have 1 wavefront. Actually, cause workgroup size of all kernels != 64, some CU will have no wavefronts at all and some will have 4 waves in that point.

Definitely. That's why I do tests on 2 quite different GPUs - to show how different behavior can be for different hardware (and software, btw) configs.
It's so called "case study" as I understand it. And it's in progress. How well params chosen from such tests will behave in real-world situation further phases will show. But it should be started from something. As with any "real" study I trying to exclude as much different factors as I can to better understand the influence of remaining ones.
For example, when I collected real-life data from my netbook I saw great deviation in run times w/o real clue what caused it.
Now I have good illustration of display state influence (in real world I can't control that cause sometimes I beside keyboard sometimes not). 
Moreover, I expect that different param configs will react differently on additional CPU load. So I need baseline with CPU idle to understand what come from loaded CPU and what comes from change of params...

EDIT: I would say this thread not about some direct recommendations what params to use but about better understanding how those params can influent on performance and what additional factors to consider when tuning performed. I think such additional knowledge can be useful too.