Thanks timenut, I have read a lot on other forums for this comparison, in summary...
3570- the authentic version, with Hesalite and steel case back with correct wording, some extra maintenance to up keep the Hesalite, love the crisp sound when you tap it with finger nail.
3573- sapphire tends to create a milky ring on the edge, but very clear and readable overall without the warm glare on Hesalite, and not so accurate wording on the case back, but you will see the beautiful movement, and of course no maintenance on the sapphire unless you chip or shatter it, and it cost more to replace than a Hesalite.
3572- Hesalite/ sapphire sandwich, best of both world, but out of production, only in preloved market.
After all, nobody can determine which is superior to which, beauty lies in the eyes of the beholder, and Speedy pro is indeed very much desirable... Talking about Speedy, hmm... I'm a bit intoxicated by the Mach4.5 after reading the vintage section...

thanks to Jos!
