Anyone have any input on a Nikon spotting scope EDIII. Currently one of the big three is not an option. Is the 60mm objective suitable to take advantage of the 20 to 60 zoom? Durability is a concern as this is primarily advertised as a birdwatching scope. Optically I don't believe there will be an issue as Nikon camera lenses are top shelf. I was looking at the ed50 for the size, but my binoculars with a doubler I think would get used more. I have packed 14 to 45x in the past, the extra zoom to 60 would be nice if usable in a smaller 60 objective package. Trying to avoid going to an 80 because of the size. Thanks.