If you go to the Wilson 5000 website, (which is a much smaller silver plated coil) states a Q of 864. So an esimated Q of 1000 is reasonable at this frequency. Q factor goes way down, as you go down in frequency, and the more you shorten an antenna. These are full sized 5/8th wave base antennas at 27mhz, so the figures are more reachable.
Fiberglass is transparent at RF, but electrically is a great high voltage insulator. So his claims are based on fact, and I am probably the only one of the thread that has heard his antennas, so I know they work. He just doesn't seem to make them very often, or desires to sell them.
The silver plating, now I agree, this is more for the perfectionist, but if you have the money, you may want to try it. Those with endless pockets, an need absolute the highest performance such as the military and broadcast stations do almost always use silver plated components with their antennas, RF amplifiers, and related. Actually even the higher dollar Amateur Radio antenna tuners silver plate their inductors to reduce losses, so there must be at least some benefit to doing this.
Copper is definately weaker than aluminum, but if making the antenna out of fiberglass, this is irrelevant, as the fiberglass is the structural part of the antenna, and copper wire inside is just the electrical component of the antenna.
Again, paying the extra money to buy silver plated parts, that's your call. Copper is very close, so if using fiberglass, I think it would be very tough to see the difference on the meter, but there is a very small gain difference.
