I?ve got an Archer NAV antenna in one wing tip, and an Archer COM antenna in the other wing tip (used for COM 2). The paint is a metallic gold. The NAV antenna works perfectly for NAV and GS, with signal reception of 75 nm or more. The COM antenna is marginal, and my performance testing suggests that it is worse with the paint than it was before the aircraft was painted. My reception range before paint was over 75 nm, except for a very small range of azimuths where the station was off the other wing. Transmission range before paint was somewhere between 45 nm and 75 nm (the ground station at 45 nm answered on all azimuths, but they did not answer at 75 nm).
After paint, my COM reception range is roughly 45 nm, and the transmission range is much lower than that (I have not properly tested this).
I eventually cobbled together an ugly antenna cable hack so that I can quickly connect COM 2 to the #1 antenna (on the belly) if COM 1 ever dies. Thus I only really use COM 2 to pick up ATIS while keeping ATC on COM 1.