well, I can confirm that they worked absolutely perfectly for what I wanted. Not sure I can post any pictures of the event, but it went sort of like this:
I arrive and walk into the room. "Rats!" Instead of worrying about how I was going to get to the gantry to attach the flashgun (superclamp cunningly included in my luggage) I was now concerned that I wouldn't be able to put it anywhere. Instead of a FOH gantry with the data projector, this year we have gone upmarket and have a back-projection system.
Never mind, needs must when the devil drives, so I clambered onto a chair and made efficient use of a picture frame on the wall (we were in the Drawing Room at the Creiff Hydro - see here
http://www.crieffhydro.com/meetings-and-events/our-facilities.aspx and it is the one on the left hand wall looking forward). This allowed me to get a narrow angled beam that would cover the podium and miss the screen, allowing me to balance the projector screen (at about 1/60 f3.5 iso 400) with the flash (SB800 on just under 1/2 power). Ambient room light was about 4 stops down so backgrounds (dark coloured curtains) were essentially black. Wireless trigger with Cactus v4 - fine as long as the antenna points in the right direction. When I was sat on the podum side of the front row it worked almost flawlessly. From the back of the room it was a bit more hit and miss - not reliable enough so I reverted to being on just the front row.
I had to guess at the colour balance of the data projector. It turned out that my 1/4 CTO and shoot at 4500K for the flash was a bit pessimistic, and I could have managed without the CTO.
Could have done with the flash being more straight on as some of the modelling was rather hash. But better than nothing at all. Sat on the front shooting with focal lengths from about 20mm (wide enough on DX to get the whole stage) through to 100mm for head and shoulders shots and 200 from the back of the room on the monopod (80-200/2.
Didn't take more than 3 or 4 per speaker except during the questions session as I didn't want to distract excessively and I also was there to listen to what they were presenting. Generally pleased with the outcome.