I recently purchased a G2. The thing loves bottle caps and I find I use my other detectors instead. Any suggestions on how to tell them from coins?

Yes try this... when you get a quarter reading(suspect bottlecap 85 to 89 vdi) Keep raising the coil while swinging it. If the signal breaks up and or becomes inconsistant its a bottlecap. If the signal stays rock steady its a coin/quarter.