Three Grand Seikos, three different regulation technologies within the same house: Spring Drive's continuous glide-motion seconds hand, and two generations of pure mechanical high-frequency (Hi-Beat). None is 'better' in the abstract — they solve precision differently.
Calibre 9R65: a mechanical movement electronically regulated by a quartz crystal, with no quartz motor or battery. The result is a seconds hand that glides continuously instead of ticking, ~72 hours of power reserve, and precision that beats any traditional mechanical. Titanium case, dial textured to evoke fresh snowfall.
Calibre 9SA5: pure mechanical at 36,000 vph (5 Hz), with a twin barrel stretching power reserve to 80 hours — unusually high for a Hi-Beat. Rated accuracy of +5/-3 seconds a day, better than the classic Hi-Beat standard. Steel case, dial imitating birch bark near the Shizukuishi studio.
Calibre 9S85: the same 36,000 vph frequency as the 9SA5, but an earlier caliber generation, with ~55 hours of power reserve (versus the 9SA5's 80h). It represents Grand Seiko's classic Heritage Collection, with hand-polished Zaratsu finishing as its visual signature.
Want the continuous glide seconds hand and the best practical accuracy of the three technologies? The Snowflake with Spring Drive. Prefer pure high-frequency mechanics with the longest power reserve? The White Birch with the newer 9SA5. Want the same high frequency with the Heritage Collection's classic finish at a different entry point? The Hi-Beat 36000 with the 9S85. None of them have verified market price data in Cazador yet.