They should even survive tropical use with moderate care. The close focus has also been improved. These glasses focus down to 10 feet, certainly as close as any birder might need. The optics of the old Audubon were, obviously, its selling point. Nothing else in its price category, when it was originally introduced, came close to it.
Competition is somewhat stiffer today.
The best of the roof prism glasses are very fine indeed, and optimized porros like the Nikon Superior E series have set a unmatched standard in optical performance. The fact is, very few binoculars, in actual side by side comparisons live up to there theoretical performance. The 32 mm Superior Es easily outperform most 42 mm roof prism glasses, so the Audubon's performance is very good indeed. A more precise comparison, of course, would be with the Swarovski 8.5x42 ELs. The new Audubons easily equal the ELs center field resolution and image quality, and, they appear just a bit brighter in most lights.