The lutz prototypes are loud and put out much less flow than the DIY kits even when running the lutz on a MJ 1200 (less than the MJ 400 with single nitro hammer props I am running currently). I think this is due to his prop design - it's heavy and not as efficient as a RC boat prop that has had significant design time put into it.
I have a lutz kit sitting in a box if anyone wants it for $10 without the bracket.
I have been playing with making these, and am very impressed. I have enough supplies to make 20 of them with the mjmods CNC machined end caps, octura 1440, 1435, or 2035 props, titanium rods and carbon fiber shafts. I am testing these out right now and they are rockin'.
Doing a demo would require power tools to be hauled to the meeting, but the directions on that site are very complete - I doubt you'd learn much more from a demo. These are pretty easy to make, the hardest part is getting all the supplies for a reasonable price (if you order them all separately shipping costs a fortune - that's why I ordered extra parts).