Hey Martinm,
I can see your headed towards full testing of the Fuzion with your washer and nozzle in place. I have not had a chance to publish these results here in a more current Showdown at High Noon article yet (I just finished grad school and have spent the last two weeks moving a Penske truck across the country to California), but my results (with the gap filled) were slightly different:

Q6600 (at 3.2 GHz) with MicroRes/MCR 220/Fuzion/MCW60/MCP 655 and 1/2 inch tubing as follows:

Load (with the gap unfilled - stock) - 42.3 deg C with 1.83 gal/min flow
Load (with the gap filled - 0.5 mm washer) - 40.8 deg C with 1.93 gal/min flow
Load (with gap filled and custom nozzle) - 39.7 deg C with 1.48 gal/min flow

Hope this helps out Martinm,
Jay