I retract my statement from this entry about PIXfW being a bit rubbish [embarrass]
I was wrong - I completely overlooked the custom test configurations. Whoops.
I've now got it to do a full D3D call capture every 500ms that doesn't appear to have any impact in the performance.
Export to CSV then becomes quite useful as you can dump the raw values to Excel and actually compute some useful averages/graphs.
Back to work. Yes I do feel like a muppet. [headshake]