Question for the experts please. How does this phong case set compare to ARF (only available option). And that price differenve is it justifiable?
That depends on what you want to do with it. A Phong case is going to look like an over polished, well used 16610.
An ARF case doesn't look very convincing for a 16610 build using gen parts - and not because of the wrong radius on the outer curve of the lower CG section, or the angle of the upper rehaut quadrant. It looks like what it is, a mass produced, machine finished steel watch case.
The ARF case is better value, Phongs cases date back to a time when there were very few alternatives and are now vastly over priced, but the engraving work is nice quality, better than the Chinese.