Not to beat an old horse, but first off not all PV is solid copper, 2nd not sure that each box is swept to 3GHz (Testing seems to conflict), 3rd solid copper is for powering the LNB(s), has ZERO effect on the signal at the 1+GHz range, and if truly solid is wayyy more expensive to produce from both a material and a tooling standpoint.
If you are doing a multi room DVR or whole home connectivity DirecTV install you do need to use the solid copper for the entire install since the slave to master communications channel is at ~2.5 MHz that is the only points you need solid copper from master to slave, also EVERY CONNECTOR MUST BE TIGHT!!!!!!!! at 2.5MHz is ALOT of junk, 1 loose connector can play havoc with the entire system (loose your ground, loose your shield, cable becomes an antenna for ambient noise, raising the noise floor, screwing up the SNR or signal to noise ratio, the system gets confused, pixelizes, tiles, and pukes).
On the Dish Network side you do not need any solid copper for superdish up, the new Hopper and Joey setup can be run entirely with copper clad steel, but again EVERY CONNECTOR MUST BE TIGHT!!!! Not going to say why, all to be revealed at Dish Summit in Orlando.....