What is the difference in these types of binos other than looks and price.Bushnell Legends for example the 8x42 roof prism compared to the 8x42 porro.The porro is about $160 less and has the same features other than the PC-3 phase coating.If I understand this right dont roof prisms need a coating like this to gather more light over the porro prism.Im trying to figure out which ones to get,roof or prism,Trophy or Legend series.Im also thinking Nikon Monarch.